生长于硅纳米孔柱阵列衬底上氧化锌的场发射和气体传感性能研究
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摘要
作为一种Ⅱ-Ⅵ族直接带隙化合物半导体材料,氧化锌(ZnO)具有较宽的带隙(3.37eV)和较高的激子束缚能(60meV)以及良好的热稳定性、化学稳定性和抗辐射性能,因而在未来的电子、光电子器件领域具有广阔的应用前景。近年来,纳米ZnO因其丰富且易控的结构形貌、奇异的物理特性而成为凝聚态物理和材料研究领域的热点。硅纳米孔柱阵列(Si-NPA)是一种硅的微米纳米结构复合体系,它在微米和纳米两个尺度上具有独特的三重层次结构特点,即规则的硅柱阵列、硅柱表面的纳米多孔结构以及组成纳米孔孔壁的硅纳米单晶颗粒。Si-NPA的特殊结构和物理化学特性使其成为制备硅基纳米复合体系的理想衬底。本文以Si-NPA为衬底,采用化学气相沉积法(CVD)制备了ZnO/Si-NPA纳米复合体系,研究了制备条件对ZnO/Si-NPA形貌的调控、ZnO/Si-NPA的场发射特性、ZnO/Si-NPA对湿度及ZnO空心球对酒精等的气体传感性能。论文取得以下主要研究结果：
1、ZnO/Si-NPA的制备与形貌调控
以Si-NPA为衬底,以高纯锌粉和高纯氧气作为锌源和氧源,采用CVD技术制备了具有阵列结构特征的ZnO/Si-NPA纳米复合体系,并通过改变锌源距离、生长温度、通氧温度和氧气流量等参数,实现了对ZnO/Si-NPA表面形貌的调控。(1)保持生长温度(900℃)、通氧温度(750℃)和氧气流量(2sccm)不变,随锌源距离增大,ZnO在Si-NPA基底上的沉积量逐渐减少,形貌逐步由ZnO纳米棒簇阵列转变为ZnO纳米针簇状阵列。(2)保持锌源距离(2cm)、通氧温度(600℃)和氧气流量(2sccm)不变,随生长温度升高,ZnO在Si-NPA基底上的沉积量逐渐增加,沉积位置和形貌也发生变化。600℃时,ZnO纳米棒较短且选择性地并呈辐射状生长在硅柱顶端；700℃时,ZnO纳米棒长度增加且选择性地并呈辐射状生长于硅柱顶端；800℃时,ZnO纳米棒直径变大,密度增加,均匀生长于硅柱及柱间。(3)保持锌源距离(4cm)、生长温度(700℃)和通氧温度(600℃)不变,改变氧气流量,ZnO纳米针呈辐射状均匀地生长于硅柱顶端,形成ZnO纳米针簇阵列。随氧气流量增大,ZnO纳米针长度和密度减小,直径增加。(4)保持锌源距离(4cm)、生长温度(900℃)和氧气流量(2sccm)不变,改变通氧温度,550℃通氧时,制备出底部和顶部直径比较均一的ZnO纳米棒簇阵列,而在650℃通氧时制备出ZnO纳米针簇阵列。
2、ZnO/Si-NPA的场发射性能研究
以具有相同柱状形貌特征的Si-NPA为衬底,通过控制CVD制备条件分别制备了具有ZnO纳米棒和纳米针簇状阵列结构特征的ZnO/Si-NPA,对比研究了其场发射性能；分别以具有柱状和火山口状形貌特征的Si-NPA为衬底,采用化学水浴(CBD)法制备了硫化锌(ZnS)/Si-NPA,研究了Si-NPA衬底形貌对其场发射性能的影响。研究表明,相对于ZnO纳米棒簇状阵列,ZnO纳米针簇状阵列具有更低的开启场强,更大的场增强因子和更高的电流发射密度。与此同时,ZnS/Si-NPA柱状阵列比火山口状阵列具有更低的开启场强和更高的发射电流密度,两者的F-N曲线呈现出截然不同的特征。采用有限元法对ZnS/Si-NPA柱状和火山口状阵列中阵列单元顶端附近的电场分布进行的模拟计算结果表明,具有柱状单元的ZnS/Si-NPA顶端呈现更强的场增强效应,从而证明了衬底形貌是冷阴极场发射性能的重要控制因素之一。
3、ZnO/Si-NPA的湿度传感性能研究
以Si-NPA为衬底,制备了ZnO/Si-NPA绣球状和菜花状阵列,并通过真空蒸镀共面叉指式Ag电极,制备了相应的湿度传感器原型器件,对比研究了其相应的湿度传感性能。相对于ZnO/Si-NPA绣球状阵列,菜花状阵列具有更快的响应/恢复速度和更小的湿滞,同时具有较好的测量重复性和时间稳定性。分析表明,造成上述湿度传感性能存在较大差距的原因,主要是ZnO/Si-NPA绣球状和菜花状阵列单元中ZnO形貌、特征尺寸和结构上的不同。此外,还制备了SnO2:Sn/Si-NPA纳米复合体系并研究了其湿度传感性能。结果表明,SnO2:Sn/Si-NPA具有较高的灵敏度、较快的响应/恢复速度、较小的湿滞和较好的测量重复性和时间稳定性。研究表明,Si-NPA是制备硅基氧化物湿度传感器的理想衬底。生长于Si-NPA衬底上化合物半导体的形貌和结构特征,则对其相应的湿度传感性能具有重要作用。
4、ZnO空心球对酒精气体的传感性能研究
采用CVD法制备ZnO/Si-NPA的过程中,作为锌源的部分高纯锌粉被原位氧化形成大量的ZnO空心球。将ZnO空心球均匀涂覆在陶瓷管上,制成一种电阻型气敏传感器原型器件。对ZnO空心球酒精传感性能的测试表明,其最佳工作温度为350℃。在对酒精浓度为10-400ppm的探测范围内,ZnO空心球传感器具有较高的灵敏度(0.25/ppm)、较短的响应/恢复时间(5～12和8～12s),且其响应曲线呈现出很好的线性关系。对不同浓度酒精的循环测试结果表明,ZnO空心球传感器具有较好的测试重复性、时间稳定性和选择性(酒精相对甲醇、甲醛和苯)。基于纳米ZnO的化学性质和ZnO空心球的形貌结构特点,分析了ZnO空心球传感器的传感机制。ZnO空心球较大的比表面积导致其具有较高的灵敏度；而镂空的球状结构则有利于酒精气体的有效传输,从而使其具有较快的响应/恢复速度。ZnO空心球具有良好的酒精传感性能,是制备酒精传感器的理想材料。
As a direct wide bandgap Ⅱ-Ⅵ compound semiconductor, zinc oxide (ZnO) has a wide band gap (3.37eV), a high exciton binding energy (60meV), outstanding thermal and chemical stability and excellent radiation resistance, which make it a promising candidate in a broad applications in the fields of electronic and optoelectronic devices. In recent years, nano ZnO became a hotspot in the field of condensed matter physics and materials research, for its rich and easy-to-control structures and morphologies, and its fantastic properties. Silicon nanoporous pillar array (Si-NPA) is a silicon micro and nanometer structural composite system, possessing a triple hierarchical structure, i.e. the regular array of micro-sized silicon pillars, the high-density nanopores distributed all over the pillars, and the silicon nanocrystallites composing the pore walls. The unique structure of Si-NPA and its special physical and chemical properties make it an ideal substrate or template for silicon-based materials. Here we prepared ZnO/Si-NPA through chemical vapor deposition (CVD) method, with Si-NPA as the substrate. We studied the regulation and control of the morphology of ZnO/Si-NPA by changing the preparation conditions, the field emission characteristics of ZnO/Si-NPA, the humidity sensing properties of the ZnO/Si-NPA, and the ethanol sensing properties of ZnO hollow spheres. The main research results achieved in this thesis are listed as the followings.
1. The preparation and morphology control of ZnO/Si-NPA.
Using Si-NPA as the substrate, high-purity zinc powder and oxygen as the zinc source and the oxygen source respectively we prepared ZnO/Si-NPA nanocomposites by CVD method. The morphology of ZnO/Si-NPA can be controled by changing the distance between the zinc source and the substrate, the growth temperature, the oxygen introducing temperature and the rate of oxygen flow:(1) When maintaining the growth temperature (900℃), the oxygen introducing temperature (750℃) and the rate of oxygen flow (2sccm) unchanged, increasing the distance between the source and the substrate, the quantity of ZnO deposited on the Si-NPA substrate reduced gradually. And the ZnO nanorods cluster array gradually changed to be ZnO nanoneedles cluster array.(2) While maintaining the source-substrate distance (2cm), the oxygen introducing temperature (600℃) and the rate of oxygen flow (2sccm) unchanged, increasing the growth temperature, the deposition quantity of ZnO on the Si-NPA substrate gradually increased and their morphology changed. ZnO nanorods were short and radially, selectively distributed on the tip of the silicon pillar when the grown temperature maintained600℃. When the grown temperature reached700℃, The length of ZnO nanorods increased and maintained selectively and radially distributed around the the tip of the silicon pillar. At800℃, the diameter of ZnO nanorods became larger, the density increased and the nanorods evenly distributed on the silicon pillar and the valley between the pillars.(3) Keeping the source-substrate distance (4cm), the growth temperature (700℃) and oxygen introducing temperature (600℃) unchanged, the rate of oxygen flow changed. Under these conditions ZnO nanoneedle radially distributed on tip of the silicon pillar, forming ZnO nanoneedles cluster array. With the rate of oxygen flow increased, the length and density of ZnO nanoneedles reduced the diameter increased.(4) Maintaining the source-substrate distance (4cm), the growth temperature (900℃) and rate of oxygen flow (2sccm) unchanged, the oxygen introducing temperature changed. When the oxygen was introduced at550℃, the clustered ZnO nanorods with a relatively uniform diameter from bottom to top were obtained. When the oxygen was introduced at650℃, ZnO nanorods cluster array was obtained.
2. The field emission properties of ZnO/Si-NPA
Using the Si-NPA with the same pillar shape morphology as the substrates, the ZnO/Si-NPA with the nanorods and nanoneedles cluster array were obtained through changing the preparation conditions, and their field emission performances were studied comparatively. And using the Si-NPA with the pillar and crater shape as the substrates, the pillar and crater shape zinc sulfide (ZnS)/Si-NPA were prepared, and the morphology effect of the ZnS/Si-NPA were studied. The results showed that the nanoneedles cluster array had a lower turn on field, a larger field enhanced factor and a higher current emission density compared with the ZnO nanorods cluster array. And the ZnS/Si-NPA pillar array had a lower turn on field, a larger field enhanced factor and a higher current emission density compared with ZnS/Si-NPA crater shape array. And the F-N curves show a distinct characteristic. The electric field distribution around the tip of the unit of the pillar array and crater shape array were simulated by finite element modeling, and the results showed that the tip of the pillar unit presents a stronger field enhancement effect, indicating that the substrate morphology is one of the important factors that effect the cold cathode field emission performance.
3. The humidity sensing properties of the ZnO/Si-NPA
Using Si-NPA as the substrate, hydrangea and cauliflower shaped ZnO/Si-NPA were prepared. The corresponding humidity sensors were prepared and their humidity properties were studied. Compared with the hydrangea shaped ZnO/Si-NPA, the cauliflower shaped ZnO/Si-NPA had a shorter response and recovery time and a smaller hysteresis. In addition, the cauliflower shaped ZnO/Si-NPA had good reproducibility and long-term stability. The analysis showed that their different humidity sensing properties were caused by the difference of the morphology, characteristic size, and the structure of the ZnO nanostructure grown on Si-NPA. In addition, SnO2:Sn/Si-NPA nanocomposites were prepared and their humidity sensing performance were studied. The results showed that SnO2:Sn/Si-NPA has a high sensitivity, fast response recovery time, small hysteresis, and good reproducibility and stability. These results showed that Si-NPA is an ideal substrate for preparing a silicon based oxygen semiconductor sensors, and the morphology of the sensing material has great effect on the sensing performance, especially the morphology of the compound semiconductor plays an important role in its humidity sensing property.
4. The ethanol sensing properties of the ZnO hollow sphere.
During the procedure of preparing the ZnO/Si-NPA by CVD method, a part of the high purity zinc powder was oxidized to form a large quantity of ZnO hollow spheres. By coating the ZnO hollow spheres onto a ceramic tube a resistance gas sensor was prepared and its ethanol sensing properties were studied. The results of the ethanol sensing test showed that the optimum operating temperature of the sensor was350℃. In the whole testing concentration range of10-400ppm, the ZnO hollow spheres sensor showed a high sensitivity (0.25/ppm), a short response and recovery time (5-12s and8-12s), and the response-concentration curve was highly linear. The circular test results for different ethanol concentrations showed that the ZnO hollow sphere sensor had good reproducibility, stability and selectivity (against methanol, formaldehyde and benzene). Based on the morphology feature of the ZnO hollow sphere and the chemical properties of ZnO nanostructure, the sensing mechanism was analyzed. ZnO hollow spheres have a large specific surface area, giving it a high sensitivity, and the hollow spherical structure is conducive to effective transmission of the ethanol gas, giving it a short response and recovery time. ZnO hollow spheres showed good ethanol sensing performance and were ideal materials for the fabrication of ethanol sensor.
1、ZnO/Si-NPA的制备与形貌调控
以Si-NPA为衬底,以高纯锌粉和高纯氧气作为锌源和氧源,采用CVD技术制备了具有阵列结构特征的ZnO/Si-NPA纳米复合体系,并通过改变锌源距离、生长温度、通氧温度和氧气流量等参数,实现了对ZnO/Si-NPA表面形貌的调控。(1)保持生长温度(900℃)、通氧温度(750℃)和氧气流量(2sccm)不变,随锌源距离增大,ZnO在Si-NPA基底上的沉积量逐渐减少,形貌逐步由ZnO纳米棒簇阵列转变为ZnO纳米针簇状阵列。(2)保持锌源距离(2cm)、通氧温度(600℃)和氧气流量(2sccm)不变,随生长温度升高,ZnO在Si-NPA基底上的沉积量逐渐增加,沉积位置和形貌也发生变化。600℃时,ZnO纳米棒较短且选择性地并呈辐射状生长在硅柱顶端；700℃时,ZnO纳米棒长度增加且选择性地并呈辐射状生长于硅柱顶端；800℃时,ZnO纳米棒直径变大,密度增加,均匀生长于硅柱及柱间。(3)保持锌源距离(4cm)、生长温度(700℃)和通氧温度(600℃)不变,改变氧气流量,ZnO纳米针呈辐射状均匀地生长于硅柱顶端,形成ZnO纳米针簇阵列。随氧气流量增大,ZnO纳米针长度和密度减小,直径增加。(4)保持锌源距离(4cm)、生长温度(900℃)和氧气流量(2sccm)不变,改变通氧温度,550℃通氧时,制备出底部和顶部直径比较均一的ZnO纳米棒簇阵列,而在650℃通氧时制备出ZnO纳米针簇阵列。
2、ZnO/Si-NPA的场发射性能研究
以具有相同柱状形貌特征的Si-NPA为衬底,通过控制CVD制备条件分别制备了具有ZnO纳米棒和纳米针簇状阵列结构特征的ZnO/Si-NPA,对比研究了其场发射性能；分别以具有柱状和火山口状形貌特征的Si-NPA为衬底,采用化学水浴(CBD)法制备了硫化锌(ZnS)/Si-NPA,研究了Si-NPA衬底形貌对其场发射性能的影响。研究表明,相对于ZnO纳米棒簇状阵列,ZnO纳米针簇状阵列具有更低的开启场强,更大的场增强因子和更高的电流发射密度。与此同时,ZnS/Si-NPA柱状阵列比火山口状阵列具有更低的开启场强和更高的发射电流密度,两者的F-N曲线呈现出截然不同的特征。采用有限元法对ZnS/Si-NPA柱状和火山口状阵列中阵列单元顶端附近的电场分布进行的模拟计算结果表明,具有柱状单元的ZnS/Si-NPA顶端呈现更强的场增强效应,从而证明了衬底形貌是冷阴极场发射性能的重要控制因素之一。
3、ZnO/Si-NPA的湿度传感性能研究
以Si-NPA为衬底,制备了ZnO/Si-NPA绣球状和菜花状阵列,并通过真空蒸镀共面叉指式Ag电极,制备了相应的湿度传感器原型器件,对比研究了其相应的湿度传感性能。相对于ZnO/Si-NPA绣球状阵列,菜花状阵列具有更快的响应/恢复速度和更小的湿滞,同时具有较好的测量重复性和时间稳定性。分析表明,造成上述湿度传感性能存在较大差距的原因,主要是ZnO/Si-NPA绣球状和菜花状阵列单元中ZnO形貌、特征尺寸和结构上的不同。此外,还制备了SnO2:Sn/Si-NPA纳米复合体系并研究了其湿度传感性能。结果表明,SnO2:Sn/Si-NPA具有较高的灵敏度、较快的响应/恢复速度、较小的湿滞和较好的测量重复性和时间稳定性。研究表明,Si-NPA是制备硅基氧化物湿度传感器的理想衬底。生长于Si-NPA衬底上化合物半导体的形貌和结构特征,则对其相应的湿度传感性能具有重要作用。
4、ZnO空心球对酒精气体的传感性能研究
采用CVD法制备ZnO/Si-NPA的过程中,作为锌源的部分高纯锌粉被原位氧化形成大量的ZnO空心球。将ZnO空心球均匀涂覆在陶瓷管上,制成一种电阻型气敏传感器原型器件。对ZnO空心球酒精传感性能的测试表明,其最佳工作温度为350℃。在对酒精浓度为10-400ppm的探测范围内,ZnO空心球传感器具有较高的灵敏度(0.25/ppm)、较短的响应/恢复时间(5～12和8～12s),且其响应曲线呈现出很好的线性关系。对不同浓度酒精的循环测试结果表明,ZnO空心球传感器具有较好的测试重复性、时间稳定性和选择性(酒精相对甲醇、甲醛和苯)。基于纳米ZnO的化学性质和ZnO空心球的形貌结构特点,分析了ZnO空心球传感器的传感机制。ZnO空心球较大的比表面积导致其具有较高的灵敏度；而镂空的球状结构则有利于酒精气体的有效传输,从而使其具有较快的响应/恢复速度。ZnO空心球具有良好的酒精传感性能,是制备酒精传感器的理想材料。
As a direct wide bandgap Ⅱ-Ⅵ compound semiconductor, zinc oxide (ZnO) has a wide band gap (3.37eV), a high exciton binding energy (60meV), outstanding thermal and chemical stability and excellent radiation resistance, which make it a promising candidate in a broad applications in the fields of electronic and optoelectronic devices. In recent years, nano ZnO became a hotspot in the field of condensed matter physics and materials research, for its rich and easy-to-control structures and morphologies, and its fantastic properties. Silicon nanoporous pillar array (Si-NPA) is a silicon micro and nanometer structural composite system, possessing a triple hierarchical structure, i.e. the regular array of micro-sized silicon pillars, the high-density nanopores distributed all over the pillars, and the silicon nanocrystallites composing the pore walls. The unique structure of Si-NPA and its special physical and chemical properties make it an ideal substrate or template for silicon-based materials. Here we prepared ZnO/Si-NPA through chemical vapor deposition (CVD) method, with Si-NPA as the substrate. We studied the regulation and control of the morphology of ZnO/Si-NPA by changing the preparation conditions, the field emission characteristics of ZnO/Si-NPA, the humidity sensing properties of the ZnO/Si-NPA, and the ethanol sensing properties of ZnO hollow spheres. The main research results achieved in this thesis are listed as the followings.
1. The preparation and morphology control of ZnO/Si-NPA.
Using Si-NPA as the substrate, high-purity zinc powder and oxygen as the zinc source and the oxygen source respectively we prepared ZnO/Si-NPA nanocomposites by CVD method. The morphology of ZnO/Si-NPA can be controled by changing the distance between the zinc source and the substrate, the growth temperature, the oxygen introducing temperature and the rate of oxygen flow:(1) When maintaining the growth temperature (900℃), the oxygen introducing temperature (750℃) and the rate of oxygen flow (2sccm) unchanged, increasing the distance between the source and the substrate, the quantity of ZnO deposited on the Si-NPA substrate reduced gradually. And the ZnO nanorods cluster array gradually changed to be ZnO nanoneedles cluster array.(2) While maintaining the source-substrate distance (2cm), the oxygen introducing temperature (600℃) and the rate of oxygen flow (2sccm) unchanged, increasing the growth temperature, the deposition quantity of ZnO on the Si-NPA substrate gradually increased and their morphology changed. ZnO nanorods were short and radially, selectively distributed on the tip of the silicon pillar when the grown temperature maintained600℃. When the grown temperature reached700℃, The length of ZnO nanorods increased and maintained selectively and radially distributed around the the tip of the silicon pillar. At800℃, the diameter of ZnO nanorods became larger, the density increased and the nanorods evenly distributed on the silicon pillar and the valley between the pillars.(3) Keeping the source-substrate distance (4cm), the growth temperature (700℃) and oxygen introducing temperature (600℃) unchanged, the rate of oxygen flow changed. Under these conditions ZnO nanoneedle radially distributed on tip of the silicon pillar, forming ZnO nanoneedles cluster array. With the rate of oxygen flow increased, the length and density of ZnO nanoneedles reduced the diameter increased.(4) Maintaining the source-substrate distance (4cm), the growth temperature (900℃) and rate of oxygen flow (2sccm) unchanged, the oxygen introducing temperature changed. When the oxygen was introduced at550℃, the clustered ZnO nanorods with a relatively uniform diameter from bottom to top were obtained. When the oxygen was introduced at650℃, ZnO nanorods cluster array was obtained.
2. The field emission properties of ZnO/Si-NPA
Using the Si-NPA with the same pillar shape morphology as the substrates, the ZnO/Si-NPA with the nanorods and nanoneedles cluster array were obtained through changing the preparation conditions, and their field emission performances were studied comparatively. And using the Si-NPA with the pillar and crater shape as the substrates, the pillar and crater shape zinc sulfide (ZnS)/Si-NPA were prepared, and the morphology effect of the ZnS/Si-NPA were studied. The results showed that the nanoneedles cluster array had a lower turn on field, a larger field enhanced factor and a higher current emission density compared with the ZnO nanorods cluster array. And the ZnS/Si-NPA pillar array had a lower turn on field, a larger field enhanced factor and a higher current emission density compared with ZnS/Si-NPA crater shape array. And the F-N curves show a distinct characteristic. The electric field distribution around the tip of the unit of the pillar array and crater shape array were simulated by finite element modeling, and the results showed that the tip of the pillar unit presents a stronger field enhancement effect, indicating that the substrate morphology is one of the important factors that effect the cold cathode field emission performance.
3. The humidity sensing properties of the ZnO/Si-NPA
Using Si-NPA as the substrate, hydrangea and cauliflower shaped ZnO/Si-NPA were prepared. The corresponding humidity sensors were prepared and their humidity properties were studied. Compared with the hydrangea shaped ZnO/Si-NPA, the cauliflower shaped ZnO/Si-NPA had a shorter response and recovery time and a smaller hysteresis. In addition, the cauliflower shaped ZnO/Si-NPA had good reproducibility and long-term stability. The analysis showed that their different humidity sensing properties were caused by the difference of the morphology, characteristic size, and the structure of the ZnO nanostructure grown on Si-NPA. In addition, SnO2:Sn/Si-NPA nanocomposites were prepared and their humidity sensing performance were studied. The results showed that SnO2:Sn/Si-NPA has a high sensitivity, fast response recovery time, small hysteresis, and good reproducibility and stability. These results showed that Si-NPA is an ideal substrate for preparing a silicon based oxygen semiconductor sensors, and the morphology of the sensing material has great effect on the sensing performance, especially the morphology of the compound semiconductor plays an important role in its humidity sensing property.
4. The ethanol sensing properties of the ZnO hollow sphere.
During the procedure of preparing the ZnO/Si-NPA by CVD method, a part of the high purity zinc powder was oxidized to form a large quantity of ZnO hollow spheres. By coating the ZnO hollow spheres onto a ceramic tube a resistance gas sensor was prepared and its ethanol sensing properties were studied. The results of the ethanol sensing test showed that the optimum operating temperature of the sensor was350℃. In the whole testing concentration range of10-400ppm, the ZnO hollow spheres sensor showed a high sensitivity (0.25/ppm), a short response and recovery time (5-12s and8-12s), and the response-concentration curve was highly linear. The circular test results for different ethanol concentrations showed that the ZnO hollow sphere sensor had good reproducibility, stability and selectivity (against methanol, formaldehyde and benzene). Based on the morphology feature of the ZnO hollow sphere and the chemical properties of ZnO nanostructure, the sensing mechanism was analyzed. ZnO hollow spheres have a large specific surface area, giving it a high sensitivity, and the hollow spherical structure is conducive to effective transmission of the ethanol gas, giving it a short response and recovery time. ZnO hollow spheres showed good ethanol sensing performance and were ideal materials for the fabrication of ethanol sensor.
引文
[1]Wang Z L, Song J H, Piezoelectric nanogenerators based on zinc oxide nanowire arrays [J]. Science,2006,312:242-246.
[2]Pan C, Yu R, Niu S, etc. Piezotronic effect on the sensitivity and signal level of schottky contacted proactive micro/nanowire nanosensors [J]. ACS nano,2013,7:1803-10.
[3]Yu R, Pan C, Wang Z L. High performance of ZnO nanowire protein sensors enhanced by the piezotronic effect [J]. Energy & Environmental Science,2013,6:494-499.
[4]Huang M H, Mao S, Feick H, etc. Room-temperature ultraviolet nanowire nanolasers [J]. Science,2001,292:1897-1899.
[5]Johnson J C, Yan H Q, Schaller R D, etc. Single nanowire lasers [J]. Journal of Physical Chemistry B,2001,105:11387-11390.
[6]Ozgur U, Alivov Ya I, Liu C, etc. A comprehensive review of ZnO materials and devices [J]. Journal of Applied Physics,2005,98:041301.
[7]Wang Z L, Kong X Y, Ding Y, etc. Semiconducting and piezoelectric oxide nanostructures induced by polar surfaces [J]. Advanced Functional Materials,2004,14:943-956.
[8]Choi Y S, Kang J W, Hwang D K, etc. Recent advances in ZnO-based light-emitting diodes [J]. Ieee Transactions on Electron Devices,2010,57:26-41.
[9]Liu K, Sakurai M, Aono M, ZnO-based ultraviolet photodetectors [J]. Sensors,2010,10: 8604-8634.
[10]Wang J X, Wu C M L, Cheung W S, etc. Synthesis of hierarchical porous ZnO disklike nanostructures for improved photovoltaic properties of dye-sensitized solar cells [J]. Journal of Physical Chemistry C,2010,114:13157-13161.
[11]Gluba M A, Nickel N H, Hinrichs K, etc. Improved passivation of the ZnO/Si interface by pulsed laser deposition [J]. Journal of Applied Physics,2013,113:043502.
[12]Vanmaekelbergh D, Van Vugt L K, ZnO nanowire lasers [J]. Nanoscale,2011,3:2783-2800.
[13]Yang R, Qin Y, Dai L, etc. Power generation with laterally packaged piezoelectric fine wires [J]. Nature Nanotechnology,2009,4:34-39.
[14]Choi M Y, Choi D, Jin M J, etc. Mechanically powered transparent flexible charge-generating nanodevices with piezoelectric ZnO nanorods [J]. Advanced Materials,2009,21:2185.
[15]Lee Y M, Huang C M, Chen H W, etc. Low temperature solution-processed ZnO nanorod arrays with application to liquid ethanol sensors [J]. Sensors and Actuators a-Physical,2013, 189:307-312.
[16]Nguyen D K, Do D T, Nguyen V D, etc. Design of SnO2/ZnO hierarchical nanostructures for enhanced ethanol gas-sensing performance [J]. Sensors and Actuators B-Chemical,2012, 174:594-601.
[17]Tamaekong N, Liewhiran C, Wisitsoraat A, etc. Acetylene sensor based on Pt/ZnO thick films as prepared by flame spray pyrolysis [J]. Sensors and Actuators:B Chemical,2011,152: 155-61.
[18]Zhang L, Zhao J, Zheng J, etc. Hydrothermal synthesis of hierarchical nanoparticle-decorated ZnO microdisks and the structure-enhanced acetylene sensing properties at high temperatures [J]. Sensors and Actuators B-Chemical,2011,158:144-150.
[19]Datta N, Ramgir N, Kaur M, etc. Selective H2S sensing characteristics of hydrothermally grown ZnO-nanowires network tailored by ultrathin CuO layers [J]. Sensors and Actuators B-Chemical,2012,166:394-401.
[20]Kim J, Kim W, Yong K. CuO/ZnO heterostructured nanorods:Photochemical synthesis and the mechanism of H2S gas sensing [J]. Journal of Physical Chemistry C,2012,116: 15682-15691.
[21]Amin M, Manzoor U, Islam M, etc. Synthesis of ZnO nanostructures for low temperature CO and UV sensing [J]. Sensors,2012,12:13842-13851.
[22]Choi S W, Kim S S, Room temperature CO sensing of selectively grown networked ZnO nanowires by pd nanodot functionalization [J]. Sensors and Actuators B-Chemical,2012,168: 8-13.
[23]Djurisic Aleksandra B, Leung Yu Hang. Optical properties of zno nanostructures [J]. Small, 2006,2:944-961.
[24]Yunhua H, Xuedong B, Yue Z. In situ mechanical properties of individual ZnO nanowires and the mass measurement of nanoparticles [J]. Journal of Physics:Condensed Matter,2006, 18:179-84.
[25]Huang Y, Zhang Y, Gu Y, etc. Field emission of a single In-doped ZnO nanowire [J]. Journal of Physical Chemistry C,2007,111:9039-9043.
[26]Xu H J, Li X J, Rectification effect and electron transport property of CdS/Si nanoheterostructure based on silicon nanoporous pillar array [J]. Applied Physics Letters, 2008,93.
[27]Hsin-Ming C, Hsu-Cheng H, Yung-Kuan T, etc. Raman scattering and efficient UV photoluminescence from well-aligned ZnO nanowires epitaxially grown on gan buffer layer [J]. Journal of Physical Chemistry B,2005,109:8749-54.
[28]Huang Y H, He J, Zhang Y, etc. Morphology, structures and properties of ZnO nanobelts fabricated by Zn-powder evaporation without catalyst at lower temperature [J]. Journal of Materials Science,2006,41:3057-3062.
[29]Li Y, You L, Duan R, etc. Oxidation of a ZnS nanobelt into a ZnO nanotwin belt or double single-crystalline ZnO nanobelts [J]. Solid State Communications,2004,129:233-238.
[30]Congkang X, Dongeon K, Junghwan C, etc. Temperature-controlled growth of ZnO nanowires and nanoplates in the temperature range 250-300℃ [J]. Journal of Physical Chemistry B,2006,110:21741-6.
[31]Xiang Y K, Yong D, Rusen Y, etc. Single-crystal nanorings formed by epitaxial self-coiling of polar nanobelts [J]. Science,2004,303:1348-51.
[32]Kong X Y, Wang Z L. Spontaneous polarization-induced nanohelixes, nanosprings, and nanorings of piezoelectric nanobelts [J]. Nano Letters,2003,3:1625-1631.
[33]Segawa Y, Ohtomo A, Kawasaki M, etc. Growth of ZnO thin film by laser mbe:Lasing of exciton at room temperature [J]. Physica Status Solidi B,1997,202:669-72.
[34]Johnson J C, Yan H, Schaller R D, etc. Single nanowire lasers [J]. The Journal of Physical Chemistry B,2001,105:11387-11390.
[35]Jiao S J, Zhang Z Z, Lu Y M, etc. ZnO p-n junction light-emitting diodes fabricated on sapphire substrates [J]. Applied Physics Letters,2006,88.
[36]Wei Z P, Lu Y M, Shen D Z, etc. Room temperature p-n ZnO blue-violet light-emitting diodes [J]. Applied Physics Letters,2007,90.
[37]Hwang D K, Kang S H, Lim J H, etc. P-ZnO/n-GaN heterostructure ZnO light-emitting diodes [J]. Applied Physics Letters,2005,86.
[38]Tsukazaki A, Ohtomo A, Onuma T, etc. Repeated temperature modulation epitaxy for p-type doping and light-emitting diode based on ZnO [J]. Nature Materials,2005,4:42-46.
[39]Johnson J C, Yan H Q, Yang P D, etc. Optical cavity effects in ZnO nanowire lasers and waveguides [J]. Journal of Physical Chemistry B,2003,107:8816-8828.
[40]Voss T, Svacha G T, Mazur E, etc. High-order waveguide modes in ZnO nanowires [J]. Nano Letters,2007,7:3675-3680.
[41]Park W I, Yi G C, Kim J W, etc. Schottky nanocontacts on ZnO nanorod arrays [J]. Applied Physics Letters,2003,82:4358-4360.
[42]Chang S L, Jin L, Puxian G, etc. ZnO nanobelt/nanowire schottky diodes formed by dielectrophoresis alignment across Au electrodes [J]. Nano Letters,2006,6:4 pp.-4 pp.
[43]Yong K P, Umar A., Jin-Seok K, etc. Single ZnO nanowire based high-performance field effect transistors (fets) [J]. Journal of Nanoscience and Nanotechnology,2009,9:5839-44.
[44]Jeong W J, Kim S K, Park G C, Preparation and characteristic of ZnO thin film with high and low resistivity for an application of solar cell [J]. Thin Solid Films,2006,506-507:180-183.
[45]Gao R, Tian J, Liang Z, etc. Nanorod-nanosheet hierarchically structured ZnO crystals on zinc foil as flexible photoanodes for dye-sensitized solar cells [J]. Nanoscale,2013,5: 1894-901.
[46]Manthina V, Baena J P C, Liu G, etc. ZnO-TiO2 nanocomposite films for high light harvesting efficiency and fast electron transport in dye-sensitized solar cells [J]. Journal of Physical Chemistry C,2012,116:23864-23870.
[47]De J P E, Vanmaekelbergh D, Trap-limited electronic transport in assemblies of nanometer-size TiO2 particles [J]. Physical Review Letters,1996,77:3427-30.
[48]Min G Peng D, Xindong W, etc. The effect of hydrothermal growth temperature on preparation and photoelectrochemical performance of ZnO nanorod array films [J]. Journal of Solid State Chemistry,2005,178:3210-15.
[49]Min G, Peng D, Shengmin Cai. Hydrothermal growth of perpendicularly oriented ZnO nanorod array film and its photoelectrochemical properties [J]. Applied Surface Science, 2005,249:71-5.
[50]Xiu-Xia Z, Chang-Chun Z, Field-emission lighting tube with CNT film cathode [J]. Microelectronics Journal,2006,37:1358-60.
[51]Pandey A, Prasad A, Moscatello J P, etc. Stable electron field emission from PMMA-CNT matrices [J]. Acs Nano,2010,4:6760-6766.
[52]Shen G Z, Bando Y, Liu B D, etc. Characterization and field-emission properties of vertically aligned ZnO nanonails and nanopencils fabricated by a modified thermal-evaporation process [J]. Advanced Functional Materials,2006,16:410-416.
[53]Wang W, Zeng B, Yang J, etc. Aligned ultralong ZnO nanobelts and their enhanced field emission [J]. Advanced Materials,2006,18:3275.
[54]Wei A, Sun X W, Xu C X, etc. Stable field emission from hydrothermally grown ZnO nanotubes [J]. Applied Physics Letters,2006,88.
[55]Lee C J, Lee T J, Lyu S C, etc. Field emission from well-aligned zinc oxide nanowires grown at low temperature [J]. Applied Physics Letters,2002,81:3648-3650.
[56]Huang Y, Bai X, Zhang Y, etc. Field-emission properties of individual ZnO nanowires studied in situ by transmission electron microscopy [J]. Journal of Physics-Condensed Matter,2007, 19.
[57]Hui P, Yanwu Z, Han S, etc. Electroluminescence and field emission of mg-doped ZnO tetrapods [J]. Nanotechnology,2006,17:5096-100.
[58]Zhao Q, Xu X Y, Song X F, etc. Enhanced field emission from zno nanorods via thermal annealing in oxygen [J]. Applied Physics Letters,2006,88.
[59]Xu C X, Sun X W, Chen B J, Field emission from gallium-doped zinc oxide nanofiber array [J]. Applied Physics Letters,2004,84:1540-1542.
[60]Pan Nan, Xue Haizhou, Yu Minghui, etc. Tip-morphology-dependent field emission from ZnO nanorod arrays [J]. Nanotechnology,2010,21.
[61]Liu N, Fang G, Zeng W, etc. Diminish the screen effect in field emission via patterned and selective edge growth of ZnO nanorod arrays [J]. Applied Physics Letters,2009,95.
[62]Zhou J, Gu Y, Hu Y, etc. Gigantic enhancement in response and reset time of ZnO UV nanosensor by utilizing schottky contact and surface functionalization [J]. Applied Physics Letters,2009,94.
[63]Wang X, Zhou J, Song J, etc. Piezoelectric field effect transistor and nanoforce sensor based on a single ZnO nanowire [J]. Nano Letters,2006,6:2768-2772.
[64]Wang J X, Sun X W, Wei A, etc. Zinc oxide nanocomb biosensor for glucose detection [J]. Applied Physics Letters,2006,88.
[65]Kumar N, Dorfman A, Hahm J, Ultrasensitive DNA sequence detection using nanoscale ZnO sensor arrays [J]. Nanotechnology,2006,17:2875-2881.
[66]Fan Z Y, Wang D W, Chang P C, etc. ZnO nanowire field-effect transistor and oxygen sensing property [J]. Applied Physics Letters,2004,85:5923-5925.
[67]Ahn M W, Park K S, Heo J H, etc. Gas sensing properties of defect-controlled ZnO nanowire gas sensor [J]. Applied Physics Letters,2008,93.
[68]Bai S, Chen L, Li D, etc. Different morphologies of ZnO nanorods and their sensing property [J]. Sensors and Actuators B-Chemical,2010,146:129-137.
[69]Huang J, Wu Y, Gu C, etc. Large-scale synthesis of flowerlike ZnO nanostructure by a simple chemical solution route and its gas-sensing property [J]. Sensors and Actuators B-Chemical, 2010,146:206-212.
[70]Meng F, Yin J, Duan Y Q, etc. Co-precipitation synthesis and gas-sensing properties of ZnO hollow sphere with porous shell [J]. Sensors and Actuators B-Chemical,2011,156:703-708.
[71]Huang J, Wu Y, Gu C, etc. Fabrication and gas-sensing properties of hierarchically porous ZnO architectures [J]. Sensors and Actuators B-Chemical,2011,155:126-133.
[72]Wang C H, Chu X F, Wu M W, Detection of H2S down to ppb levels at room temperature using sensors based on ZnO nanorods [J]. Sensors and Actuators B-Chemical,2006,113: 320-323.
[73]Jing Z, Zhan J, Fabrication and gas-sensing properties of porous ZnO nanoplates [J]. Advanced Materials,2008,20:4547-4551.
[74]Qi Q, Zhang T, Yu Q, etc. Properties of humidity sensing ZnO nanorods-base sensor fabricated by screen-printing [J]. Sensors and Actuators B-Chemical,2008,133:638-643.
[75]Wang W, Li Z, Liu L, etc. Humidity sensor based on LiCl-doped ZnO electrospun nanofibers [J]. Sensors and Actuators B-Chemical,2009,141:404-409.
[76]Xu H J, Li X J, Silicon nanoporous pillar array:A silicon hierarchical structure with high light absorption and triple-band photoluminescence [J]. Optics Express,2008,16:2933-2941.
[77]Xin J L, Xing H, Yu J, etc. Tunable superstructures in hydrothermally etched iron-passivated porous silicon [J]. Applied Physics Letters,1999,75:2906-8.
[78]李亚勤,孙新瑞,许海军等。制备条件对硅纳米孔柱阵列表面硅柱密度调制[J].科学技术与工程,2008,11：2806-2810.
[79]Feng F, Zhi G, Jia H S, etc. Sers detection of low-concentration adenine by a patterned silver structure immersion plated on a silicon nanoporous pillar array [J]. Nanotechnology,2009,20: 295501-295501.
[80]Fu X N, Li X J. Enhanced field emission from well-patterned silicon nanoporous pillar arrays [J]. Chinese Physics Letters,2006,23:2172-2174.
[81]Yang X H, Jiang W F, Li X J. Preparation technique for copper-plating on si nanoporous pillar array [J]. Thin Solid Films,2010,518:6866-9.
[82]FU X N, Li X J, Enhanced field emission from well-patterned silicon nanoporous pillar arrays [J]. Chinese Physics Letters,2006,23:2172-2174.
[83]Han C B, He C, Li X J. Near-infrared light emission from a Ga/si nanoheterostructure array [J]. Advanced Materials,2011,23:4811.
[84]He C, Han C B, Xu Y R, etc. Photovoltaic effect of CdS/si nanoheterojunction array [J]. Journal of Applied Physics,2011,110:094316-094316.
[85]Li X J, Jiang W F, Enhanced field emission from a nest array of multi-walled carbon nanotubes grown on a silicon nanoporous pillar array [J]. Nanotechnology,2007,18:065203.
[86]Wang H Y, Li X J, Structural and capacitive humidity sensing properties of nanocrystal magnetite/silicon nanoporous pillar array [J]. Sensors and Actuators B-Chemical,2005,110: 260-263.
[87]Jiang W F, Xiao S H, Feng C Y, etc. Resistive humidity sensitivity of arrayed multi-wall carbon nanotube nests grown on arrayed nanoporous silicon pillars [J]. Sensors and Actuators B-Chemical,2007,125:651-655.
[88]Wang H Y, Wang Y Q, Hu Q F, etc. Capacitive humidity sensing properties of SiC nanowires grown on silicon nanoporous pillar array [J]. Sensors and Actuators B-Chemical,2012,166: 451-456.
[89]Wang H Y, Wang Y Q, Chen H Y, etc. Room-temperature H2S gas sensing properties of carbonized silicon nanoporous pillar array [J]. Thin Solid Films,2012,520:4436-4438.
[90]Fan H J, Werner P, Zacharias M, Semiconductor nanowires:From self-organization to patterned growth [J]. Small,2006,2:700-717.
[91]Mohammad S N, General hypothesis governing the growth of single-crystal nanowires [J]. Journal of Applied Physics,2010,107.
[92]Westwater J, Gosain D P, Tomiya S, etc., Growth of silicon nanowires via gold/silane vapor-liquid-solid reaction [J]. Journal of Vacuum Science & Technology B (Microelectronics and Nanometer Structures),1997,15:554-7.
[93]Mohammad S N, Analysis of the vapor-liquid-solid mechanism for nanowire growth and a model for this mechanism [J]. Nano Letters,2008,8:1532-1538.
[94]Lee S T, Wang N, Lee C S, Semiconductor nanowires:Synthesis, structure and properties [J]. Materials Science & Engineering A (Structural Materials:Properties, Microstructure and Processing),2000, A286:16-23.
[95]Shen G Z, Bando Y, Lee C J, Synthesis and evolution of novel hollow ZnO urchins by a simple thermal evaporation process [J]. Journal of Physical Chemistry B,2005,109: 10578-10583.
[96]Castaneda L, Synthesis and characterization of ZnO micro-and nano-cages [J]. Acta Materialia,2009,57:1385-1391.
[97]Fang X, Bando Y, Gautam U K, etc. Inorganic semiconductor nanostructures and their field-emission applications [J]. Journal of Materials Chemistry,2008,18:509-522.
[98]Xu C X, Sun X W, Field emission from zinc oxide nanopins [J]. Applied Physics Letters, 2003,83:3806-3808.
[99]Yang H Y, Lau S P, Yu S F, etc., Field emission from zinc oxide nanoneedles on plastic substrates [J]. Nanotechnology,2005,16:1300-1303.
[100]Zhai T, Li L, Ma Y, etc. One-dimensional inorganic nanostructures:Synthesis, field-emission and photodetection [J]. Chemical Society Reviews,2011,40:2986-3004.
[101]McCarthy E, Garry S, Byrne D, etc., Field emission in ordered arrays of ZnO nanowires prepared by nanosphere lithography and extended fowler-nordheim analyses [J]. Journal of Applied Physics,2011,110.
[102]Chen Z H, Tang Y B, Liu Y, etc., ZnO nanowire arrays grown on Al:ZnO buffer layers and their enhanced electron field emission [J]. Journal of Applied Physics,2009,106.
[103]Cao B, Teng X, Heo S H, etc., Different ZnO nanostructures fabricated by a seed-layer assisted electrochemical route and their photoluminescence and field emission properties [J]. Journal of Physical Chemistry C,2007,111:2470-2476.
[104]Li L M, Du Z F, Li C C, etc., Ultralow threshold field emission from ZnO nanorod arrays grown on ZnO film at low temperature [J]. Nanotechnology,2007,18.
[105]Zhang Y, Lee C T, Site-controlled growth and field emission properties of ZnO nanorod arrays [J]. Journal of Physical Chemistry C,2009,113:5920.
[106]Niemann Da L, Ribaya Bryan P, Gunther N, etc., Effects of cathode structure on the field emission properties of individual multi-walled carbon nanotube emitters [J]. Nanotechnology, 2007,18.
[107]Rezeq M, Finite element simulation and analytical analysis for nano field emission sources that terminate with a single atom:A new perspective on nanotips [J]. Applied Surface Science, 2012,258:4091-4091.
[108]Chen Z G, Zou J, Liu G, etc., Growth, cathodoluminescence and field emission of ZnS tetrapod tree-like heterostructures [J]. Advanced Functional Materials,2008,18:3063-3069.
[109]Chen S, Li L, Wang X, etc., Dense and vertically-aligned centimetre-long ZnS nanowire arrays:Ionic liquid assisted synthesis and their field emission properties [J]. Nanoscale,2012, 4:2658-2662.
[110]Qian G, Huo K, Fu J, etc., Direct growth of quasi-aligned ultrafine ZnS nanowire arrays on conducting zinc foils and their field emission properties [J]. Journal of Nanoscience and Nanotechnology,2009,9:3347-51.
[111]Choi Y C, Shin Y M, Bae D J, etc., Patterned growth and field emission properties of vertically aligned carbon nanotubes [J]. Diamond and Related Materials,2001,10: 1457-1464.
[112]Ramgir N S, Late D J, Bhise A B, etc. Field emission studies of novel ZnO nanostructures in high and low field regions [J]. Nanotechnology,2006,17:2730-2735.
[113]Xu C X, Sun X W, Fang S N, etc. Electrochemically deposited zinc oxide arrays for field emission [J]. Applied Physics Letters,2006,88.
[114]Cao B Q, Cai W P, Duan G T, etc., A template-free electrochemical deposition route to ZnO nanoneedle arrays and their optical and field emission properties [J]. Nanotechnology,2005, 16:2567-2574.
[115]Fang X, Bando Y, Shen G, etc., Ultrarine ZnS nanobelts as field emitters [J]. Advanced Materials,2007,19:2593.
[116]Liu B, Bando Y, Jiang X, etc. Self-assembled ZnS nanowire arrays:Synthesis, in situ Cu doping and field emission [J]. Nanotechnology,2010,21.
[117]Hafeez M, Zhai T, Bhatti A S, etc. Enhanced field emission and optical properties of controlled tapered ZnS nanostructures [J]. Journal of Physical Chemistry C,2012,116: 8297-8304.
[118]Chen Z, Lu C, Humidity sensors:A review of materials and mechanisms [J]. Sensor Letters, 2005,3:274-295.
[119]Chou K S, Lee T K, Liu F J, Sensing mechanism of a porous ceramic as humidity sensor [J]. Sensors and Actuators B -Chemical,1999,56:106-11.
[120]Traversa E., Ceramic sensors for humidity detection:The state-of-the-art and future developments [J]. Sensors and Actuators B (Chemical),1995, B23:135-56.
[121]Yeo T L, Sun T, Grattan K T V, Fibre-optic sensor technologies for humidity and moisture measurement [J]. Sensors and Actuators A-Physical,2008,144:280-295.
[122]Chen H J, Xue Q Z, Ma Ming, etc. Capacitive humidity sensor based on amorphous carbon film/n-si heterojunctions [J]. Sensors and Actuators B-Chemical,2010,150:487-489.
[123]Sundaram R, Raj E S, Nagaraja K S, Microwave assisted synthesis, characterization and humidity dependent electrical conductivity studies of perovskite oxides, Sm-1-xSrxCrO3 (0 <= x<=0.1) [J]. Sensors and Actuators B-Chemical,2004,99:350-354.
[124]Tao B, Zhang J, Miao F, etc., Capacitive humidity sensors based on Ni/SiNWs nanocomposites [J]. Sensors and Actuators B-Chemical,2009,136:144-150.
[125]Qiu Y, Yang S, ZnO nanotetrapods:Controlled vapor-phase synthesis and application for humidity sensing [J]. Advanced Functional Materials,2007,17:1345-1352.
[126]Hu X, Gong J, Zhang L, etc., Continuous size tuning of monodisperse ZnO colloidal nanocrystal clusters by a microwave-polyol process and their application for humidity sensing [J]. Advanced Materials,2008,20:4845.
[127]Li L Y, Dong Y F, Jiang W F, etc., High-performance capacitive humidity sensor based on silicon nanoporous pillar array [J]. Thin Solid Films,2008,517:948-951.
[128]Lee C Y, Lee G B, Humidity sensors:A review [J]. Sensor Letters,2005,3:1-15.
[129]Rittersma Z M, Recent achievements in miniaturised humidity sensors-a review of transduction techniques [J]. Sensors and Actuators A-Physical,2002,96:196-210.
[130]Yuan Q, Li N, Tu J, etc., Preparation and humidity sensitive property of mesoporous ZnO-SiO2 composite [J]. Sensors and Actuators B-Chemical,2010,149:413-419.
[131]Biaggi-Labiosa A, Sola F, Lebron-Colon M, etc., A novel methane sensor based on porous SnO2 nanorods:Room temperature to high temperature detection [J]. Nanotechnology,2012, 23.
[132]Feng H, Huang J, Li J, A mechanical actuated SnO2 nanowire for small molecules sensing [J]. Chemical Communications,2013,49:1017-1019.
[133]Sun G J, Choi S W, Jung S H, etc. V-groove SnO2 nanowire sensors:Fabrication and pt-nanoparticle decoration [J]. Nanotechnology,2013,24.
[134]Zhang J B, Li X N, Bai S L, etc., High-yield synthesis of SnO2 nanobelts by water-assisted chemical vapor deposition for sensor applications [J]. Materials Research Bulletin,2012,47: 3277-3282.
[135]Datta N, Ramgir N, Kaur M, etc., Vacuum deposited WO3 thin films based sub-ppm H2S sensor [J]. Materials Chemistry and Physics,2012,134:851-857.
[136]Gao G, Wu J, Wu G, etc., Phase transition effect on durability of WO3 hydrogen sensing films:An insight by experiment and first-principle method [J]. Sensors and Actuators B-Chemical,2012,171:1288-1291.
[137]Zhao M, Huang J X, Ong C W, Room-temperature resistive H-2 sensing response of Pd/WO3 nanocluster-based highly porous film [J]. Nanotechnology,2012,23.
[138 Gu C, Xu X, Huang J, etc., Porous flower-like SnO2 nanostructures as sensitive gas sensors for volatile organic compounds detection [J]. Sensors and Actuators B-Chemical,2012,174: 31-38.
[139 Huang J, Xu X, Gu C, etc., Effective VOCs gas sensor based on porous SnO2 microcubes prepared via spontaneous phase segregation [J]. Sensors and Actuators B-Chemical,2012, 173:599-606.
[140]Kim H, Jin C, Park S, etc., Enhanced H2S gas sensing properties of multiple-networked pd-doped SnO2-core/ZnO-shell nanorod sensors [J]. Materials Research Bulletin,2012,47: 2708-2712.
[141]Lin Z, Song W, Yang H, Highly sensitive gas sensor based on coral-like SnO2 prepared with hydrothermal treatment [J]. Sensors and Actuators B-Chemical,2012,173:22-27.
[142]Li L,, Yu K, Wu J, etc. Structure and humidity sensing properties of SnO2 zigzag belts [J]. Crystal Research and Technology,2010,45:539-44.
[143]Kuang Q, Lao C, Wang Z L, etc., High-sensitivity humidity sensor based on a single SnO2 nanowire [J]. Journal of the American Chemical Society,2007,129:6070.
[144]Parthibavarman M, Hariharan V, Sekar C, High-sensitivity humidity sensor based on SnO2 nanoparticles synthesized by microwave irradiation method [J]. Materials Science & Engineering C-Materials for Biological Applications,2011,31:840-844.
[145]Gyger F, Huebner M, Feldmann C, etc., Nanoscale SnO2 hollow spheres and their application as a gas-sensing material [J]. Chemistry of Materials,2010,22:4821-4827.
[146]Yin X M, Li C C, Zhang M, etc., SnO2 monolayer porous hollow spheres as a gas sensor [J]. Nanotechnology,2009,20(45):455503-455503.
[147]Lee C Y, Kim S J, Hwang I S, etc., Glucose-mediated hydrothermal synthesis and gas sensing characteristics of WO3 hollow microspheres [J]. Sensors and Actuators B-Chemical, 2009,142:236-242.
[148]Gang Y, Peng H, Yuebin C, etc., Fabrication of porous TiO2 hollow spheres and their application in gas sensing [J]. Nano Scale Research Letters,2010,5:1437-41.
[149]Chen Y, Zhu C L, Xiao G, Ethanol sensing characteristics of ambient temperature sonochemically synthesized ZnO nanotubes [J]. Sensors and Actuators B-Chemical,2008, 129:639-642.
[150]Zhu C L, Chen Y J, Wang R X, etc., Synthesis and enhanced ethanol sensing properties of alpha-Fe2O3/ZnO heteronanostructures [J]. Sensors and Actuators B-Chemical,2009,140: 185-189.
[151]Chen Y, Zhu C L, Xiao G, Reduced-temperature ethanol sensing characteristics of flower-like ZnO nanorods synthesized by a sonochemical method [J]. Nanotechnology,2006, 17:4537-4541.
[2]Pan C, Yu R, Niu S, etc. Piezotronic effect on the sensitivity and signal level of schottky contacted proactive micro/nanowire nanosensors [J]. ACS nano,2013,7:1803-10.
[3]Yu R, Pan C, Wang Z L. High performance of ZnO nanowire protein sensors enhanced by the piezotronic effect [J]. Energy & Environmental Science,2013,6:494-499.
[4]Huang M H, Mao S, Feick H, etc. Room-temperature ultraviolet nanowire nanolasers [J]. Science,2001,292:1897-1899.
[5]Johnson J C, Yan H Q, Schaller R D, etc. Single nanowire lasers [J]. Journal of Physical Chemistry B,2001,105:11387-11390.
[6]Ozgur U, Alivov Ya I, Liu C, etc. A comprehensive review of ZnO materials and devices [J]. Journal of Applied Physics,2005,98:041301.
[7]Wang Z L, Kong X Y, Ding Y, etc. Semiconducting and piezoelectric oxide nanostructures induced by polar surfaces [J]. Advanced Functional Materials,2004,14:943-956.
[8]Choi Y S, Kang J W, Hwang D K, etc. Recent advances in ZnO-based light-emitting diodes [J]. Ieee Transactions on Electron Devices,2010,57:26-41.
[9]Liu K, Sakurai M, Aono M, ZnO-based ultraviolet photodetectors [J]. Sensors,2010,10: 8604-8634.
[10]Wang J X, Wu C M L, Cheung W S, etc. Synthesis of hierarchical porous ZnO disklike nanostructures for improved photovoltaic properties of dye-sensitized solar cells [J]. Journal of Physical Chemistry C,2010,114:13157-13161.
[11]Gluba M A, Nickel N H, Hinrichs K, etc. Improved passivation of the ZnO/Si interface by pulsed laser deposition [J]. Journal of Applied Physics,2013,113:043502.
[12]Vanmaekelbergh D, Van Vugt L K, ZnO nanowire lasers [J]. Nanoscale,2011,3:2783-2800.
[13]Yang R, Qin Y, Dai L, etc. Power generation with laterally packaged piezoelectric fine wires [J]. Nature Nanotechnology,2009,4:34-39.
[14]Choi M Y, Choi D, Jin M J, etc. Mechanically powered transparent flexible charge-generating nanodevices with piezoelectric ZnO nanorods [J]. Advanced Materials,2009,21:2185.
[15]Lee Y M, Huang C M, Chen H W, etc. Low temperature solution-processed ZnO nanorod arrays with application to liquid ethanol sensors [J]. Sensors and Actuators a-Physical,2013, 189:307-312.
[16]Nguyen D K, Do D T, Nguyen V D, etc. Design of SnO2/ZnO hierarchical nanostructures for enhanced ethanol gas-sensing performance [J]. Sensors and Actuators B-Chemical,2012, 174:594-601.
[17]Tamaekong N, Liewhiran C, Wisitsoraat A, etc. Acetylene sensor based on Pt/ZnO thick films as prepared by flame spray pyrolysis [J]. Sensors and Actuators:B Chemical,2011,152: 155-61.
[18]Zhang L, Zhao J, Zheng J, etc. Hydrothermal synthesis of hierarchical nanoparticle-decorated ZnO microdisks and the structure-enhanced acetylene sensing properties at high temperatures [J]. Sensors and Actuators B-Chemical,2011,158:144-150.
[19]Datta N, Ramgir N, Kaur M, etc. Selective H2S sensing characteristics of hydrothermally grown ZnO-nanowires network tailored by ultrathin CuO layers [J]. Sensors and Actuators B-Chemical,2012,166:394-401.
[20]Kim J, Kim W, Yong K. CuO/ZnO heterostructured nanorods:Photochemical synthesis and the mechanism of H2S gas sensing [J]. Journal of Physical Chemistry C,2012,116: 15682-15691.
[21]Amin M, Manzoor U, Islam M, etc. Synthesis of ZnO nanostructures for low temperature CO and UV sensing [J]. Sensors,2012,12:13842-13851.
[22]Choi S W, Kim S S, Room temperature CO sensing of selectively grown networked ZnO nanowires by pd nanodot functionalization [J]. Sensors and Actuators B-Chemical,2012,168: 8-13.
[23]Djurisic Aleksandra B, Leung Yu Hang. Optical properties of zno nanostructures [J]. Small, 2006,2:944-961.
[24]Yunhua H, Xuedong B, Yue Z. In situ mechanical properties of individual ZnO nanowires and the mass measurement of nanoparticles [J]. Journal of Physics:Condensed Matter,2006, 18:179-84.
[25]Huang Y, Zhang Y, Gu Y, etc. Field emission of a single In-doped ZnO nanowire [J]. Journal of Physical Chemistry C,2007,111:9039-9043.
[26]Xu H J, Li X J, Rectification effect and electron transport property of CdS/Si nanoheterostructure based on silicon nanoporous pillar array [J]. Applied Physics Letters, 2008,93.
[27]Hsin-Ming C, Hsu-Cheng H, Yung-Kuan T, etc. Raman scattering and efficient UV photoluminescence from well-aligned ZnO nanowires epitaxially grown on gan buffer layer [J]. Journal of Physical Chemistry B,2005,109:8749-54.
[28]Huang Y H, He J, Zhang Y, etc. Morphology, structures and properties of ZnO nanobelts fabricated by Zn-powder evaporation without catalyst at lower temperature [J]. Journal of Materials Science,2006,41:3057-3062.
[29]Li Y, You L, Duan R, etc. Oxidation of a ZnS nanobelt into a ZnO nanotwin belt or double single-crystalline ZnO nanobelts [J]. Solid State Communications,2004,129:233-238.
[30]Congkang X, Dongeon K, Junghwan C, etc. Temperature-controlled growth of ZnO nanowires and nanoplates in the temperature range 250-300℃ [J]. Journal of Physical Chemistry B,2006,110:21741-6.
[31]Xiang Y K, Yong D, Rusen Y, etc. Single-crystal nanorings formed by epitaxial self-coiling of polar nanobelts [J]. Science,2004,303:1348-51.
[32]Kong X Y, Wang Z L. Spontaneous polarization-induced nanohelixes, nanosprings, and nanorings of piezoelectric nanobelts [J]. Nano Letters,2003,3:1625-1631.
[33]Segawa Y, Ohtomo A, Kawasaki M, etc. Growth of ZnO thin film by laser mbe:Lasing of exciton at room temperature [J]. Physica Status Solidi B,1997,202:669-72.
[34]Johnson J C, Yan H, Schaller R D, etc. Single nanowire lasers [J]. The Journal of Physical Chemistry B,2001,105:11387-11390.
[35]Jiao S J, Zhang Z Z, Lu Y M, etc. ZnO p-n junction light-emitting diodes fabricated on sapphire substrates [J]. Applied Physics Letters,2006,88.
[36]Wei Z P, Lu Y M, Shen D Z, etc. Room temperature p-n ZnO blue-violet light-emitting diodes [J]. Applied Physics Letters,2007,90.
[37]Hwang D K, Kang S H, Lim J H, etc. P-ZnO/n-GaN heterostructure ZnO light-emitting diodes [J]. Applied Physics Letters,2005,86.
[38]Tsukazaki A, Ohtomo A, Onuma T, etc. Repeated temperature modulation epitaxy for p-type doping and light-emitting diode based on ZnO [J]. Nature Materials,2005,4:42-46.
[39]Johnson J C, Yan H Q, Yang P D, etc. Optical cavity effects in ZnO nanowire lasers and waveguides [J]. Journal of Physical Chemistry B,2003,107:8816-8828.
[40]Voss T, Svacha G T, Mazur E, etc. High-order waveguide modes in ZnO nanowires [J]. Nano Letters,2007,7:3675-3680.
[41]Park W I, Yi G C, Kim J W, etc. Schottky nanocontacts on ZnO nanorod arrays [J]. Applied Physics Letters,2003,82:4358-4360.
[42]Chang S L, Jin L, Puxian G, etc. ZnO nanobelt/nanowire schottky diodes formed by dielectrophoresis alignment across Au electrodes [J]. Nano Letters,2006,6:4 pp.-4 pp.
[43]Yong K P, Umar A., Jin-Seok K, etc. Single ZnO nanowire based high-performance field effect transistors (fets) [J]. Journal of Nanoscience and Nanotechnology,2009,9:5839-44.
[44]Jeong W J, Kim S K, Park G C, Preparation and characteristic of ZnO thin film with high and low resistivity for an application of solar cell [J]. Thin Solid Films,2006,506-507:180-183.
[45]Gao R, Tian J, Liang Z, etc. Nanorod-nanosheet hierarchically structured ZnO crystals on zinc foil as flexible photoanodes for dye-sensitized solar cells [J]. Nanoscale,2013,5: 1894-901.
[46]Manthina V, Baena J P C, Liu G, etc. ZnO-TiO2 nanocomposite films for high light harvesting efficiency and fast electron transport in dye-sensitized solar cells [J]. Journal of Physical Chemistry C,2012,116:23864-23870.
[47]De J P E, Vanmaekelbergh D, Trap-limited electronic transport in assemblies of nanometer-size TiO2 particles [J]. Physical Review Letters,1996,77:3427-30.
[48]Min G Peng D, Xindong W, etc. The effect of hydrothermal growth temperature on preparation and photoelectrochemical performance of ZnO nanorod array films [J]. Journal of Solid State Chemistry,2005,178:3210-15.
[49]Min G, Peng D, Shengmin Cai. Hydrothermal growth of perpendicularly oriented ZnO nanorod array film and its photoelectrochemical properties [J]. Applied Surface Science, 2005,249:71-5.
[50]Xiu-Xia Z, Chang-Chun Z, Field-emission lighting tube with CNT film cathode [J]. Microelectronics Journal,2006,37:1358-60.
[51]Pandey A, Prasad A, Moscatello J P, etc. Stable electron field emission from PMMA-CNT matrices [J]. Acs Nano,2010,4:6760-6766.
[52]Shen G Z, Bando Y, Liu B D, etc. Characterization and field-emission properties of vertically aligned ZnO nanonails and nanopencils fabricated by a modified thermal-evaporation process [J]. Advanced Functional Materials,2006,16:410-416.
[53]Wang W, Zeng B, Yang J, etc. Aligned ultralong ZnO nanobelts and their enhanced field emission [J]. Advanced Materials,2006,18:3275.
[54]Wei A, Sun X W, Xu C X, etc. Stable field emission from hydrothermally grown ZnO nanotubes [J]. Applied Physics Letters,2006,88.
[55]Lee C J, Lee T J, Lyu S C, etc. Field emission from well-aligned zinc oxide nanowires grown at low temperature [J]. Applied Physics Letters,2002,81:3648-3650.
[56]Huang Y, Bai X, Zhang Y, etc. Field-emission properties of individual ZnO nanowires studied in situ by transmission electron microscopy [J]. Journal of Physics-Condensed Matter,2007, 19.
[57]Hui P, Yanwu Z, Han S, etc. Electroluminescence and field emission of mg-doped ZnO tetrapods [J]. Nanotechnology,2006,17:5096-100.
[58]Zhao Q, Xu X Y, Song X F, etc. Enhanced field emission from zno nanorods via thermal annealing in oxygen [J]. Applied Physics Letters,2006,88.
[59]Xu C X, Sun X W, Chen B J, Field emission from gallium-doped zinc oxide nanofiber array [J]. Applied Physics Letters,2004,84:1540-1542.
[60]Pan Nan, Xue Haizhou, Yu Minghui, etc. Tip-morphology-dependent field emission from ZnO nanorod arrays [J]. Nanotechnology,2010,21.
[61]Liu N, Fang G, Zeng W, etc. Diminish the screen effect in field emission via patterned and selective edge growth of ZnO nanorod arrays [J]. Applied Physics Letters,2009,95.
[62]Zhou J, Gu Y, Hu Y, etc. Gigantic enhancement in response and reset time of ZnO UV nanosensor by utilizing schottky contact and surface functionalization [J]. Applied Physics Letters,2009,94.
[63]Wang X, Zhou J, Song J, etc. Piezoelectric field effect transistor and nanoforce sensor based on a single ZnO nanowire [J]. Nano Letters,2006,6:2768-2772.
[64]Wang J X, Sun X W, Wei A, etc. Zinc oxide nanocomb biosensor for glucose detection [J]. Applied Physics Letters,2006,88.
[65]Kumar N, Dorfman A, Hahm J, Ultrasensitive DNA sequence detection using nanoscale ZnO sensor arrays [J]. Nanotechnology,2006,17:2875-2881.
[66]Fan Z Y, Wang D W, Chang P C, etc. ZnO nanowire field-effect transistor and oxygen sensing property [J]. Applied Physics Letters,2004,85:5923-5925.
[67]Ahn M W, Park K S, Heo J H, etc. Gas sensing properties of defect-controlled ZnO nanowire gas sensor [J]. Applied Physics Letters,2008,93.
[68]Bai S, Chen L, Li D, etc. Different morphologies of ZnO nanorods and their sensing property [J]. Sensors and Actuators B-Chemical,2010,146:129-137.
[69]Huang J, Wu Y, Gu C, etc. Large-scale synthesis of flowerlike ZnO nanostructure by a simple chemical solution route and its gas-sensing property [J]. Sensors and Actuators B-Chemical, 2010,146:206-212.
[70]Meng F, Yin J, Duan Y Q, etc. Co-precipitation synthesis and gas-sensing properties of ZnO hollow sphere with porous shell [J]. Sensors and Actuators B-Chemical,2011,156:703-708.
[71]Huang J, Wu Y, Gu C, etc. Fabrication and gas-sensing properties of hierarchically porous ZnO architectures [J]. Sensors and Actuators B-Chemical,2011,155:126-133.
[72]Wang C H, Chu X F, Wu M W, Detection of H2S down to ppb levels at room temperature using sensors based on ZnO nanorods [J]. Sensors and Actuators B-Chemical,2006,113: 320-323.
[73]Jing Z, Zhan J, Fabrication and gas-sensing properties of porous ZnO nanoplates [J]. Advanced Materials,2008,20:4547-4551.
[74]Qi Q, Zhang T, Yu Q, etc. Properties of humidity sensing ZnO nanorods-base sensor fabricated by screen-printing [J]. Sensors and Actuators B-Chemical,2008,133:638-643.
[75]Wang W, Li Z, Liu L, etc. Humidity sensor based on LiCl-doped ZnO electrospun nanofibers [J]. Sensors and Actuators B-Chemical,2009,141:404-409.
[76]Xu H J, Li X J, Silicon nanoporous pillar array:A silicon hierarchical structure with high light absorption and triple-band photoluminescence [J]. Optics Express,2008,16:2933-2941.
[77]Xin J L, Xing H, Yu J, etc. Tunable superstructures in hydrothermally etched iron-passivated porous silicon [J]. Applied Physics Letters,1999,75:2906-8.
[78]李亚勤,孙新瑞,许海军等。制备条件对硅纳米孔柱阵列表面硅柱密度调制[J].科学技术与工程,2008,11：2806-2810.
[79]Feng F, Zhi G, Jia H S, etc. Sers detection of low-concentration adenine by a patterned silver structure immersion plated on a silicon nanoporous pillar array [J]. Nanotechnology,2009,20: 295501-295501.
[80]Fu X N, Li X J. Enhanced field emission from well-patterned silicon nanoporous pillar arrays [J]. Chinese Physics Letters,2006,23:2172-2174.
[81]Yang X H, Jiang W F, Li X J. Preparation technique for copper-plating on si nanoporous pillar array [J]. Thin Solid Films,2010,518:6866-9.
[82]FU X N, Li X J, Enhanced field emission from well-patterned silicon nanoporous pillar arrays [J]. Chinese Physics Letters,2006,23:2172-2174.
[83]Han C B, He C, Li X J. Near-infrared light emission from a Ga/si nanoheterostructure array [J]. Advanced Materials,2011,23:4811.
[84]He C, Han C B, Xu Y R, etc. Photovoltaic effect of CdS/si nanoheterojunction array [J]. Journal of Applied Physics,2011,110:094316-094316.
[85]Li X J, Jiang W F, Enhanced field emission from a nest array of multi-walled carbon nanotubes grown on a silicon nanoporous pillar array [J]. Nanotechnology,2007,18:065203.
[86]Wang H Y, Li X J, Structural and capacitive humidity sensing properties of nanocrystal magnetite/silicon nanoporous pillar array [J]. Sensors and Actuators B-Chemical,2005,110: 260-263.
[87]Jiang W F, Xiao S H, Feng C Y, etc. Resistive humidity sensitivity of arrayed multi-wall carbon nanotube nests grown on arrayed nanoporous silicon pillars [J]. Sensors and Actuators B-Chemical,2007,125:651-655.
[88]Wang H Y, Wang Y Q, Hu Q F, etc. Capacitive humidity sensing properties of SiC nanowires grown on silicon nanoporous pillar array [J]. Sensors and Actuators B-Chemical,2012,166: 451-456.
[89]Wang H Y, Wang Y Q, Chen H Y, etc. Room-temperature H2S gas sensing properties of carbonized silicon nanoporous pillar array [J]. Thin Solid Films,2012,520:4436-4438.
[90]Fan H J, Werner P, Zacharias M, Semiconductor nanowires:From self-organization to patterned growth [J]. Small,2006,2:700-717.
[91]Mohammad S N, General hypothesis governing the growth of single-crystal nanowires [J]. Journal of Applied Physics,2010,107.
[92]Westwater J, Gosain D P, Tomiya S, etc., Growth of silicon nanowires via gold/silane vapor-liquid-solid reaction [J]. Journal of Vacuum Science & Technology B (Microelectronics and Nanometer Structures),1997,15:554-7.
[93]Mohammad S N, Analysis of the vapor-liquid-solid mechanism for nanowire growth and a model for this mechanism [J]. Nano Letters,2008,8:1532-1538.
[94]Lee S T, Wang N, Lee C S, Semiconductor nanowires:Synthesis, structure and properties [J]. Materials Science & Engineering A (Structural Materials:Properties, Microstructure and Processing),2000, A286:16-23.
[95]Shen G Z, Bando Y, Lee C J, Synthesis and evolution of novel hollow ZnO urchins by a simple thermal evaporation process [J]. Journal of Physical Chemistry B,2005,109: 10578-10583.
[96]Castaneda L, Synthesis and characterization of ZnO micro-and nano-cages [J]. Acta Materialia,2009,57:1385-1391.
[97]Fang X, Bando Y, Gautam U K, etc. Inorganic semiconductor nanostructures and their field-emission applications [J]. Journal of Materials Chemistry,2008,18:509-522.
[98]Xu C X, Sun X W, Field emission from zinc oxide nanopins [J]. Applied Physics Letters, 2003,83:3806-3808.
[99]Yang H Y, Lau S P, Yu S F, etc., Field emission from zinc oxide nanoneedles on plastic substrates [J]. Nanotechnology,2005,16:1300-1303.
[100]Zhai T, Li L, Ma Y, etc. One-dimensional inorganic nanostructures:Synthesis, field-emission and photodetection [J]. Chemical Society Reviews,2011,40:2986-3004.
[101]McCarthy E, Garry S, Byrne D, etc., Field emission in ordered arrays of ZnO nanowires prepared by nanosphere lithography and extended fowler-nordheim analyses [J]. Journal of Applied Physics,2011,110.
[102]Chen Z H, Tang Y B, Liu Y, etc., ZnO nanowire arrays grown on Al:ZnO buffer layers and their enhanced electron field emission [J]. Journal of Applied Physics,2009,106.
[103]Cao B, Teng X, Heo S H, etc., Different ZnO nanostructures fabricated by a seed-layer assisted electrochemical route and their photoluminescence and field emission properties [J]. Journal of Physical Chemistry C,2007,111:2470-2476.
[104]Li L M, Du Z F, Li C C, etc., Ultralow threshold field emission from ZnO nanorod arrays grown on ZnO film at low temperature [J]. Nanotechnology,2007,18.
[105]Zhang Y, Lee C T, Site-controlled growth and field emission properties of ZnO nanorod arrays [J]. Journal of Physical Chemistry C,2009,113:5920.
[106]Niemann Da L, Ribaya Bryan P, Gunther N, etc., Effects of cathode structure on the field emission properties of individual multi-walled carbon nanotube emitters [J]. Nanotechnology, 2007,18.
[107]Rezeq M, Finite element simulation and analytical analysis for nano field emission sources that terminate with a single atom:A new perspective on nanotips [J]. Applied Surface Science, 2012,258:4091-4091.
[108]Chen Z G, Zou J, Liu G, etc., Growth, cathodoluminescence and field emission of ZnS tetrapod tree-like heterostructures [J]. Advanced Functional Materials,2008,18:3063-3069.
[109]Chen S, Li L, Wang X, etc., Dense and vertically-aligned centimetre-long ZnS nanowire arrays:Ionic liquid assisted synthesis and their field emission properties [J]. Nanoscale,2012, 4:2658-2662.
[110]Qian G, Huo K, Fu J, etc., Direct growth of quasi-aligned ultrafine ZnS nanowire arrays on conducting zinc foils and their field emission properties [J]. Journal of Nanoscience and Nanotechnology,2009,9:3347-51.
[111]Choi Y C, Shin Y M, Bae D J, etc., Patterned growth and field emission properties of vertically aligned carbon nanotubes [J]. Diamond and Related Materials,2001,10: 1457-1464.
[112]Ramgir N S, Late D J, Bhise A B, etc. Field emission studies of novel ZnO nanostructures in high and low field regions [J]. Nanotechnology,2006,17:2730-2735.
[113]Xu C X, Sun X W, Fang S N, etc. Electrochemically deposited zinc oxide arrays for field emission [J]. Applied Physics Letters,2006,88.
[114]Cao B Q, Cai W P, Duan G T, etc., A template-free electrochemical deposition route to ZnO nanoneedle arrays and their optical and field emission properties [J]. Nanotechnology,2005, 16:2567-2574.
[115]Fang X, Bando Y, Shen G, etc., Ultrarine ZnS nanobelts as field emitters [J]. Advanced Materials,2007,19:2593.
[116]Liu B, Bando Y, Jiang X, etc. Self-assembled ZnS nanowire arrays:Synthesis, in situ Cu doping and field emission [J]. Nanotechnology,2010,21.
[117]Hafeez M, Zhai T, Bhatti A S, etc. Enhanced field emission and optical properties of controlled tapered ZnS nanostructures [J]. Journal of Physical Chemistry C,2012,116: 8297-8304.
[118]Chen Z, Lu C, Humidity sensors:A review of materials and mechanisms [J]. Sensor Letters, 2005,3:274-295.
[119]Chou K S, Lee T K, Liu F J, Sensing mechanism of a porous ceramic as humidity sensor [J]. Sensors and Actuators B -Chemical,1999,56:106-11.
[120]Traversa E., Ceramic sensors for humidity detection:The state-of-the-art and future developments [J]. Sensors and Actuators B (Chemical),1995, B23:135-56.
[121]Yeo T L, Sun T, Grattan K T V, Fibre-optic sensor technologies for humidity and moisture measurement [J]. Sensors and Actuators A-Physical,2008,144:280-295.
[122]Chen H J, Xue Q Z, Ma Ming, etc. Capacitive humidity sensor based on amorphous carbon film/n-si heterojunctions [J]. Sensors and Actuators B-Chemical,2010,150:487-489.
[123]Sundaram R, Raj E S, Nagaraja K S, Microwave assisted synthesis, characterization and humidity dependent electrical conductivity studies of perovskite oxides, Sm-1-xSrxCrO3 (0 <= x<=0.1) [J]. Sensors and Actuators B-Chemical,2004,99:350-354.
[124]Tao B, Zhang J, Miao F, etc., Capacitive humidity sensors based on Ni/SiNWs nanocomposites [J]. Sensors and Actuators B-Chemical,2009,136:144-150.
[125]Qiu Y, Yang S, ZnO nanotetrapods:Controlled vapor-phase synthesis and application for humidity sensing [J]. Advanced Functional Materials,2007,17:1345-1352.
[126]Hu X, Gong J, Zhang L, etc., Continuous size tuning of monodisperse ZnO colloidal nanocrystal clusters by a microwave-polyol process and their application for humidity sensing [J]. Advanced Materials,2008,20:4845.
[127]Li L Y, Dong Y F, Jiang W F, etc., High-performance capacitive humidity sensor based on silicon nanoporous pillar array [J]. Thin Solid Films,2008,517:948-951.
[128]Lee C Y, Lee G B, Humidity sensors:A review [J]. Sensor Letters,2005,3:1-15.
[129]Rittersma Z M, Recent achievements in miniaturised humidity sensors-a review of transduction techniques [J]. Sensors and Actuators A-Physical,2002,96:196-210.
[130]Yuan Q, Li N, Tu J, etc., Preparation and humidity sensitive property of mesoporous ZnO-SiO2 composite [J]. Sensors and Actuators B-Chemical,2010,149:413-419.
[131]Biaggi-Labiosa A, Sola F, Lebron-Colon M, etc., A novel methane sensor based on porous SnO2 nanorods:Room temperature to high temperature detection [J]. Nanotechnology,2012, 23.
[132]Feng H, Huang J, Li J, A mechanical actuated SnO2 nanowire for small molecules sensing [J]. Chemical Communications,2013,49:1017-1019.
[133]Sun G J, Choi S W, Jung S H, etc. V-groove SnO2 nanowire sensors:Fabrication and pt-nanoparticle decoration [J]. Nanotechnology,2013,24.
[134]Zhang J B, Li X N, Bai S L, etc., High-yield synthesis of SnO2 nanobelts by water-assisted chemical vapor deposition for sensor applications [J]. Materials Research Bulletin,2012,47: 3277-3282.
[135]Datta N, Ramgir N, Kaur M, etc., Vacuum deposited WO3 thin films based sub-ppm H2S sensor [J]. Materials Chemistry and Physics,2012,134:851-857.
[136]Gao G, Wu J, Wu G, etc., Phase transition effect on durability of WO3 hydrogen sensing films:An insight by experiment and first-principle method [J]. Sensors and Actuators B-Chemical,2012,171:1288-1291.
[137]Zhao M, Huang J X, Ong C W, Room-temperature resistive H-2 sensing response of Pd/WO3 nanocluster-based highly porous film [J]. Nanotechnology,2012,23.
[138 Gu C, Xu X, Huang J, etc., Porous flower-like SnO2 nanostructures as sensitive gas sensors for volatile organic compounds detection [J]. Sensors and Actuators B-Chemical,2012,174: 31-38.
[139 Huang J, Xu X, Gu C, etc., Effective VOCs gas sensor based on porous SnO2 microcubes prepared via spontaneous phase segregation [J]. Sensors and Actuators B-Chemical,2012, 173:599-606.
[140]Kim H, Jin C, Park S, etc., Enhanced H2S gas sensing properties of multiple-networked pd-doped SnO2-core/ZnO-shell nanorod sensors [J]. Materials Research Bulletin,2012,47: 2708-2712.
[141]Lin Z, Song W, Yang H, Highly sensitive gas sensor based on coral-like SnO2 prepared with hydrothermal treatment [J]. Sensors and Actuators B-Chemical,2012,173:22-27.
[142]Li L,, Yu K, Wu J, etc. Structure and humidity sensing properties of SnO2 zigzag belts [J]. Crystal Research and Technology,2010,45:539-44.
[143]Kuang Q, Lao C, Wang Z L, etc., High-sensitivity humidity sensor based on a single SnO2 nanowire [J]. Journal of the American Chemical Society,2007,129:6070.
[144]Parthibavarman M, Hariharan V, Sekar C, High-sensitivity humidity sensor based on SnO2 nanoparticles synthesized by microwave irradiation method [J]. Materials Science & Engineering C-Materials for Biological Applications,2011,31:840-844.
[145]Gyger F, Huebner M, Feldmann C, etc., Nanoscale SnO2 hollow spheres and their application as a gas-sensing material [J]. Chemistry of Materials,2010,22:4821-4827.
[146]Yin X M, Li C C, Zhang M, etc., SnO2 monolayer porous hollow spheres as a gas sensor [J]. Nanotechnology,2009,20(45):455503-455503.
[147]Lee C Y, Kim S J, Hwang I S, etc., Glucose-mediated hydrothermal synthesis and gas sensing characteristics of WO3 hollow microspheres [J]. Sensors and Actuators B-Chemical, 2009,142:236-242.
[148]Gang Y, Peng H, Yuebin C, etc., Fabrication of porous TiO2 hollow spheres and their application in gas sensing [J]. Nano Scale Research Letters,2010,5:1437-41.
[149]Chen Y, Zhu C L, Xiao G, Ethanol sensing characteristics of ambient temperature sonochemically synthesized ZnO nanotubes [J]. Sensors and Actuators B-Chemical,2008, 129:639-642.
[150]Zhu C L, Chen Y J, Wang R X, etc., Synthesis and enhanced ethanol sensing properties of alpha-Fe2O3/ZnO heteronanostructures [J]. Sensors and Actuators B-Chemical,2009,140: 185-189.
[151]Chen Y, Zhu C L, Xiao G, Reduced-temperature ethanol sensing characteristics of flower-like ZnO nanorods synthesized by a sonochemical method [J]. Nanotechnology,2006, 17:4537-4541.