Ag掺杂ZnSb基热电薄膜的膜层结构和热电性能
|
摘要
ZnSb基热电材料是中温区热电性能较好的一种材料,为进一步提升其性能,采用磁控溅射(射频+直流)的方法制备掺杂型ZnSb基热电薄膜;通过改变溅射功率控制Ag元素的掺杂量,通过真空退火来实现掺杂元素的均匀化和膜层的结晶,真空退火温度选用300℃,退火时间为1 h。利用扫描电子显微镜(SEM)、X射线衍射仪(XRD)、霍尔效应测试仪、薄膜Seebeck系数测量系统对薄膜特性进行测试;研究Ag掺杂对ZnSb基热电薄膜膜层结构和热电性能的影响。结果表明:随着Ag掺杂量的增加,薄膜的膜层结构显著改善,掺杂后薄膜中出现Ag_3Sb和Zn_4Sb_3两种新相;掺杂后薄膜的热电性能相比未掺杂薄膜的提升较大,掺杂对薄膜的Seebeck系数也产生了较大的影响。当Ag掺杂量(摩尔分数)为2.88%时,样品获得最大的功率因子,在573K温度下功率因子为1.979 mW/(m·K~2)。
The ZnSb-based thermoelectric material is a kind of material with good thermoelectric properties in middle temperature region. In order to further improve its performance, ZnSb thermoelectric thin films were fabricated by magnetron sputtering(RF+DC) with the Zn-Sb binary composite target. The doping amount of the Ag element was controlled by changing the sputtering power. The annealing temperature was 300 ℃ and the annealing time was 1 h; the homogenization of the dopant elements and the crystallization of the samples were carried out by vacuum annealing. The properties of the films were tested by scanning electron microscopy(SEM), X-ray diffractometry(XRD), Hall effect tester and thin film Seebeck coefficient measurement system. The effects of doping on the structure and thermoelectric properties of ZnSb-based thermoelectric thin film were studied. The results show that the film structure of the sample improves significantly with the increase of the amount of Ag doping. After the doping, two new phases, Ag_3 Sb and Zn_4 Sb_3, appear in the doped film. The thermoelectric properties of the doped films improves compared to those of the films without doping. The dopant has a great influence on the Seebeck coefficient of the sample film. It is concluded that the two new phases, Ag_3 Sb and Zn_4 Sb_3 form after doping are the key factors that cause the structure and thermoelectric properties of ZnSb-based thermoelectric thin film.
The ZnSb-based thermoelectric material is a kind of material with good thermoelectric properties in middle temperature region. In order to further improve its performance, ZnSb thermoelectric thin films were fabricated by magnetron sputtering(RF+DC) with the Zn-Sb binary composite target. The doping amount of the Ag element was controlled by changing the sputtering power. The annealing temperature was 300 ℃ and the annealing time was 1 h; the homogenization of the dopant elements and the crystallization of the samples were carried out by vacuum annealing. The properties of the films were tested by scanning electron microscopy(SEM), X-ray diffractometry(XRD), Hall effect tester and thin film Seebeck coefficient measurement system. The effects of doping on the structure and thermoelectric properties of ZnSb-based thermoelectric thin film were studied. The results show that the film structure of the sample improves significantly with the increase of the amount of Ag doping. After the doping, two new phases, Ag_3 Sb and Zn_4 Sb_3, appear in the doped film. The thermoelectric properties of the doped films improves compared to those of the films without doping. The dopant has a great influence on the Seebeck coefficient of the sample film. It is concluded that the two new phases, Ag_3 Sb and Zn_4 Sb_3 form after doping are the key factors that cause the structure and thermoelectric properties of ZnSb-based thermoelectric thin film.
引文
[1]HAN Chao,LI Zhen,DOU Shi-xue.Recent progress in thermoelectric materials[J].Chinese Science Bulletin,2014,59(18):2073-2091.
[2]VINING C B.An inconvenient truth about thermoelectrics[J].Nature Materials,2009,8(2):83-85.
[3]尹振忠,朱铁军,沈俊杰,杨胜辉,赵新兵.制备工艺对N型Bi2Te2.4Se0.6合金热电性能的影响[J].中国有色金属学报,2011,21(8):1916-1920.YIN Zhen-zhong,ZHU Tie-jun,SHEN Jun-jie,YANGSheng-hui,ZHAO Xin-bing.Effect of preparation methods on thermoelectric properties of N-type Bi2Te2.4Se0.6 bulk alloys[J].The Chinese Journal of Nonferrous Metals,2011,21(8):1916-1920.
[4]ZHANG Xiao,ZHAO Li-dong.Thermoelectric materials:Energy conversion between heat and electricity[J].Journal of Materiomics,2015:1-31.
[5]BELL L E.Cooling,heating,generating power,and recovering waste heat with thermoelectric systems[J].Science,2008,321(5895):1457-1461.
[6]POTHIN R,AYRAL R M.Interest of the differential analysis on the characterization of thermoelectric materials:ZnSb[J].Journal of Alloys and Compound,2016,657:358-365.
[7]PO?EGA E,IVANOV S,STEVI?Z,KARAN-OVI?L,TOMANEC R,GOMID?ELOVI?L,KOSTOV A.Identification and characterization of single crystal Bi2Te3-x Sex alloy[J].Transactions of Nonferrous Metals Society of China,2015,25(10):3279-3285.
[8]SNYDER G J,TOBERER E S.Complex thermo-electric materials[J].Nature Materials,2008,7(2):105-114.
[9]王蕾,王鸣,赵栋梁.高度织构Ni掺杂NaxCoO2氧化物的制备及其热电性能[J].中国有色金属学报,2008,18(11):2056-2061.WANG Lei,WANG Ming,ZHAO Dong-liang.Thermoelectric properties of highly textured Ni-substituted Nax CoO2 ceramics[J].The Chinese Journal of Nonferrous Metals,2008,18(11):2056-2061.
[10]SHABALDIN A A,PROKOF’EVA L V,KONSTANTINOV P P,BURKOV A T,FEDOROW M I.Acceptor impurity of copper in ZnSb thermoelectric[J].Materials Today Proceedings,2015,2(2):699-704.
[11]FEDOROV M I,PROKOFIEVA L V,RAVICH Y I,KONSTANTINOV P P,PSHENAY-SEVEVIN D A,SHABALDIN A A.Thermoelectric efficiency of intermetallic compound ZnSb[J].Semiconductors,2014,48(4):432-437.
[12]KINGA N,PHILIPPE J.Influence of exchange-correlation functional on the electronic properties of ZnSb as promising themoelectric materials[J].Journal of Electronic Materials,2015:1540-1546.
[13]ZHENG Zhuang-hao,FAN Ping.Enhanced thermoelectric properties of Cu doped ZnSb based thin films[J].Journal of Alloys and Compounds,2016,668:8-12.
[14]LI Jing-feng,LIU Wei-shu,ZHAO Li-dong,ZHOU Min.High-performance nanostructured thermoelectric materials[J].NPG Asia Materials,2010,2(4):152-158.
[15]ZHOU Yang,LI Liang-liang,TAN Qing,LI Jing-feng.Thermoelectric properties of Pb-doped bismuth telluride thin films deposited by magnetron sputtering[J].Journal of Alloys and Compounds,2014,590:362-367.
[16]ZHANG Zhi-wei,WANG Yao,DENG Yuan,TAN Ming.Growth and transport properties of layered bismuth telluride thin films via radio frequency magnetron sputtering[J].Journal of Inorganic Materials,2011,26(5):555-560.
[17]陈志坚,李建新,周白杨,温翠莲.基于复合靶溅射制备Mg2Si薄膜及其热电性能[J].中国有色金属学报,2016,26(6):1214-1221.CHEN Zhi-jian,LI Jian-xin,ZHOU Bai-yang,WEN Cui-lian.Thermoelectric properties of Mg2Si thin film prepared by magnetron sputtering based on composite target[J].The Chinese Journal of Nonferrous Metals,2016,26(6):1214-1221.
[18]CHEN Z J,ZHOU B Y,LI J X,WEN C L.Thermoelectric properties of Al-doped Mg2Si thin films deposited by magnetron sputtering[J].Applied Surface Science,2016,386:389-392.
[2]VINING C B.An inconvenient truth about thermoelectrics[J].Nature Materials,2009,8(2):83-85.
[3]尹振忠,朱铁军,沈俊杰,杨胜辉,赵新兵.制备工艺对N型Bi2Te2.4Se0.6合金热电性能的影响[J].中国有色金属学报,2011,21(8):1916-1920.YIN Zhen-zhong,ZHU Tie-jun,SHEN Jun-jie,YANGSheng-hui,ZHAO Xin-bing.Effect of preparation methods on thermoelectric properties of N-type Bi2Te2.4Se0.6 bulk alloys[J].The Chinese Journal of Nonferrous Metals,2011,21(8):1916-1920.
[4]ZHANG Xiao,ZHAO Li-dong.Thermoelectric materials:Energy conversion between heat and electricity[J].Journal of Materiomics,2015:1-31.
[5]BELL L E.Cooling,heating,generating power,and recovering waste heat with thermoelectric systems[J].Science,2008,321(5895):1457-1461.
[6]POTHIN R,AYRAL R M.Interest of the differential analysis on the characterization of thermoelectric materials:ZnSb[J].Journal of Alloys and Compound,2016,657:358-365.
[7]PO?EGA E,IVANOV S,STEVI?Z,KARAN-OVI?L,TOMANEC R,GOMID?ELOVI?L,KOSTOV A.Identification and characterization of single crystal Bi2Te3-x Sex alloy[J].Transactions of Nonferrous Metals Society of China,2015,25(10):3279-3285.
[8]SNYDER G J,TOBERER E S.Complex thermo-electric materials[J].Nature Materials,2008,7(2):105-114.
[9]王蕾,王鸣,赵栋梁.高度织构Ni掺杂NaxCoO2氧化物的制备及其热电性能[J].中国有色金属学报,2008,18(11):2056-2061.WANG Lei,WANG Ming,ZHAO Dong-liang.Thermoelectric properties of highly textured Ni-substituted Nax CoO2 ceramics[J].The Chinese Journal of Nonferrous Metals,2008,18(11):2056-2061.
[10]SHABALDIN A A,PROKOF’EVA L V,KONSTANTINOV P P,BURKOV A T,FEDOROW M I.Acceptor impurity of copper in ZnSb thermoelectric[J].Materials Today Proceedings,2015,2(2):699-704.
[11]FEDOROV M I,PROKOFIEVA L V,RAVICH Y I,KONSTANTINOV P P,PSHENAY-SEVEVIN D A,SHABALDIN A A.Thermoelectric efficiency of intermetallic compound ZnSb[J].Semiconductors,2014,48(4):432-437.
[12]KINGA N,PHILIPPE J.Influence of exchange-correlation functional on the electronic properties of ZnSb as promising themoelectric materials[J].Journal of Electronic Materials,2015:1540-1546.
[13]ZHENG Zhuang-hao,FAN Ping.Enhanced thermoelectric properties of Cu doped ZnSb based thin films[J].Journal of Alloys and Compounds,2016,668:8-12.
[14]LI Jing-feng,LIU Wei-shu,ZHAO Li-dong,ZHOU Min.High-performance nanostructured thermoelectric materials[J].NPG Asia Materials,2010,2(4):152-158.
[15]ZHOU Yang,LI Liang-liang,TAN Qing,LI Jing-feng.Thermoelectric properties of Pb-doped bismuth telluride thin films deposited by magnetron sputtering[J].Journal of Alloys and Compounds,2014,590:362-367.
[16]ZHANG Zhi-wei,WANG Yao,DENG Yuan,TAN Ming.Growth and transport properties of layered bismuth telluride thin films via radio frequency magnetron sputtering[J].Journal of Inorganic Materials,2011,26(5):555-560.
[17]陈志坚,李建新,周白杨,温翠莲.基于复合靶溅射制备Mg2Si薄膜及其热电性能[J].中国有色金属学报,2016,26(6):1214-1221.CHEN Zhi-jian,LI Jian-xin,ZHOU Bai-yang,WEN Cui-lian.Thermoelectric properties of Mg2Si thin film prepared by magnetron sputtering based on composite target[J].The Chinese Journal of Nonferrous Metals,2016,26(6):1214-1221.
[18]CHEN Z J,ZHOU B Y,LI J X,WEN C L.Thermoelectric properties of Al-doped Mg2Si thin films deposited by magnetron sputtering[J].Applied Surface Science,2016,386:389-392.