摘要
氧化锌是具有六方结构的重要功能材料，室温下能带带隙为3.3
eV，激子束缚能高达60meV，室温下在紫外波段具有强的自由激子
发光，是近年来继GaN之后国际上又一研究热点。ZnO适合于薄膜
的外延生长，原材料资源丰富、价格便宜，对环境无毒无害，在信息
显示领域有广泛的应用前景。人们以往着重于ZnO薄膜的结构和光
学特性研究，而对于绝缘介质包埋的ZnO纳米粒子的结构和光学特
性研究进行较少。制备SiO_2包埋的ZnO纳米粒子可以利用ZnO/SiO_2
形成的波导结构和量子点的光学特性显著地减小光的散射和自吸收效
应，达到增强紫外光发射强度的目的，为研究性能优良的蓝紫色发光
器件提供了新的途径。
首次在Si衬底上利用电子束蒸发石英同时热蒸发金属Zn及后退
火方法制备了具有较强紫外发射的SiO_2包埋的ZnO纳米粒子薄膜材
料，样品的表面形貌分析、红外光谱、X-射线衍射谱和X射线光电
子能谱结果表明：在700℃退火温度和氧气气氛下，随退火时间的增
加，在SiO_2内部形成了ZnO纳米粒子。微区光致发光谱显示样品中
存在着较多的缺陷，ZnO纳米粒子的粒子尺寸分布不均匀、ZnO纳
米粒子密度较低，样品中的应力和ZnO_2的形成将引起ZnO纳米粒子
的光致发光峰位的变化。随退火时间的增加，在石英内部形成的ZnO
纳米粒子的尺寸分布逐渐呈现单一分布。当考虑应力对ZnO纳米粒
子影响时，有效质量计算结果表明在SiO_2基质中形成了ZnO纳米粒
子。变温微区光致发光实验表明紫外光致发光主要来源于ZnO纳米
粒子的自由激子发光。
在160keV注入能量，首次将剂量为3×10~(17)cm~(-2)的Zn离子注入
到光学纯石英基片上，采用高温后退火方法制备了高质量的SiO_2包
埋的ZnO纳米粒子。利用X-射线衍射谱、表面形貌分析和X射线光
刘玉学：博士学位论文 摘要
电子能谱研究了退火温度、退火气氛和退火时间对ZnO 纳米粒子的
组分、取向、应力、平均粒子尺寸和纳米晶体质量的影响。实验结果
表明：退火温度对石英内部形成的ZnO 纳米粒子的取向和组分产生
重要的影响，在500℃条件下，对离子注入样品退火3小时发现石英
内部的Zn原子并未全部氧化形成ZnO纳米粒子；在900℃退火1小
时条件下，可以在石英内部形成无Zn相的ZnO纳米粒子，但在退火
过程中发主了石英内部Zn 原子的外扩散并从石英表面逸出的现象，
造成石英内部的ZnO纳米粒子的密度变小。在700℃退火条件下，
通过改变退火时间可实现对ZnO 纳米粒子的取向、平均粒子尺寸和
内部应力的控制。高剂量Zn离子注入及Zn逸出导致在注入层形成
微孔、弱键和断键，在高温热退火过程中，将发生微孔塌陷和弱键及
断键的再构，使石英表面收缩；2 小时退火能形成高质量无Zn相的
SID。包埋的高密度ZnO纳米粒子。在氮气和氧气气氛下顺次退火，
可以实现对ZnO 纳米粒子平均尺寸和密度分布的控制。在石英内部
形成的 ZnO纳米粒子的平均粒子尺寸为 18．52 urn。通过 Zn原子在
石英中扩散的动力学模拟，发现在氧气氛下热退火形成ZnO纳米粒
子的过程中，氧原子向石英内部的扩散起着重要的作用。
利用吸收光谱和微区光致发光谱首次在室温下观察到了利用离子
注入及后退火方法制备的SIOZ包埋的ZnO纳米粒子的自由激子吸收
峰和强的紫外光致发光峰。微区光致发光实验结果表明量子限制作用
和应力同时影响ZnO 纳米粒子的光致发光峰的能量；在氧气氛退火
过程中，扩散到石英表面的氧原子可以显著地减少ZnO 纳米晶体边
界的缺陷和离子注入诱导的缺陷，获得高质量的ZnO 纳米晶体。变
温微区光致发光谱结果表明：样品中的杂质沽污较少，离子注入及后
退火方法是获得高纯ZnO 纳米晶体最有效的途径之一。室温紫外发
光来源于ZnO纳米粒子的自由激子发光；在77K温度下，ZnO纳米
粒子仍呈现较强的自由激子紫外光发射，同时伴随着较弱的束缚激子
和自由激子声子伴线的发光，自由激子的发光强度随温度变化不显
2
刘玉学：博士学位论文 搁要
著、呈现了量子点发光的变化规律。
ZnO is a versatile semiconductor material with hexagona1 wurtzite
structure and has a band gap of 3.3 eV and a 1arge exciton binding energy
of 60 meV at room temperature. ZnO has attracted much more interest in
the field of the intbrmation and display like GaN due to the application
of UV emission. ZnO has some advantages, $uch as resource-richness,
cheapness and innocuity. In the past, the structure and optical properties
of ZnO film has been investigated extensively, in contrast, we are less
known about the structure and optica1 properties of ZnO nanopartic1es
embedded in dielectric tnatrix. By utilizing the wave guide structure of
ZnO/SiO, and the optica1 properties of quantum dots, ZnO nanoparticles
embedded in SiO, can decrease the intensity of the photon scattering and
se1fabsorption and increase the ZnO nanoparticles UV emission.
For the first time, ZnO nanoparticles embedded in SiO, thin fi1m
with the intense ultra-violet emission was fabricated by using electron
beam evaporation silica, synchronously thermal evaporation metal zinc
on silicon substrate and followed by post-thermal annealing. The results
of surface contour analysis, JR spectra, X-ray diffraction spectra and X-
ray photoelectron spectra indicated that ZiiO nanoparticles embedded in
SiO were formed in oxygen ambient at the annealing temperature of
7000C as the annealing time increased to 2 hours. Micro-
photoluminescence spectra showed the existence of a lot of defects, the
nonuniform distribution of ZnQ nanoparticles size and the distribution of
nanoparticles low density in Si02. As the annealing time increased, the
distribution of ZnO nanoparticles in SiO-, gradually displayed mono-
distribution of ZnO nanoparticles size. Taking into account the influence
of the stress on the energy band of ZnO nanoparticles, the results of the
effective mass approximation calculation indicated the formation of ZnO
nanoparticles embedded in SiO,. The UV emission of ZnQ nanoparticles
at room temperature can be attributed to the free exciton emission.
For the first time, high quality ZnQ nanoparticles embedded in
SiO, was fabricated by zinc ion implantation (160 keV, 3x10? cm~2) into
optical-grade silica substrate, followed by post-thermal annealing. The
dependence of the component, orientation, Stress, average grain size and
the quality of ZnO nanoparticles on the annealing temperature, ambient
and time was studied by X-ray diffraction spectra, surface contour
analysis and X-ray photoelectron spectra. The experimental results
indicated that the component and orientation of ZnO nanoparticles
embedded in Si02 were influenced by the annealing time. The annealing
time of 3 hours is not enough to oxidize zinc atom in silica at 5000C. The
ZnO nanoparticles without Zn phase embedded in SiO, were prepared at
9000C. During the annealing process, zinc atom diffusion from silica
inside to silica surface and zinc atom effusion from silica surface
occurred. The density of ZnO nanoparticles embedded in SiO, was
decreased. The annealing time can control the orientation, average grain
size and stress of ZnO nanopartic1es embedded in SiO, at 700'C. The
zinc ion implantation with high dose and zinc atoms effusion from si1ica
surface can give rise to micro-hole, weak bond and breaken bond in silica
near the implantation layer. During the annealing process, the dissppear
of micro-hole and the reconstitution of weak and breaken bond will occur.
High quality ZnO nanoparticles embedded in SiO, was obtained as the
annea1ing time increased to 2 hours at 700'C, We can control the average
grain size and density of ZnO nanopartic1es by sequentia1 post-thermal
annealing zinc-implanted si1ica in nitrogen and
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