Effect of deposited temperatures of the buffer layer on the band offset of CZTS/In2S3 heterostructure and its solar cell performance
Effect of deposited temperatures of the buffer layer on the band offset of CZTS/In2S3 heterostructure and its solar cell performance
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缓冲层沉积温度对CZTS/In2S3异质结构能带偏移及其太阳能电池性能的影响
DOI：
10.1088/1674-1056/26/4/046802
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发表时间：
2017
影响因子：
1.7
通讯作者：
Zhang Hong
中科院分区：
文献类型：
--
作者：
Yu Jinling;Zheng Zhongming;Dong Limei;Cheng Shuying;Lai Yunfeng;Zheng Qiao;Zhou Haifang;Jia Hongjie;Zhang Hong
研究了缓冲层In_2S_3的沉积温度对CZTS/In_2S_3异质结能带取向和电池性能的影响。采用热蒸发法分别在30、100、150和200 °C下制备了In 2S 3薄膜。通过使用X射线光电子能谱（XPS），对于在30、100、150和200 °C下沉积的CZTS/In 2S 3异质结构，价带偏移（VBO）分别被确定为-0.28 ± 0.1、-0.28 ±0.1、-0.34 ±0.1和-0.42 ±0.1 eV，相应的导带偏移（CBO）分别为0.3±0.1，0.41±0.1，0.22±0.1和0.01± 0.1eV。XPS研究还表明，In和Cu在异质结界面发生了相互扩散，在200 °C时这种相互扩散尤为严重，导致大量的界面缺陷或在界面处形成CuInS 2相。在150 °C下沉积缓冲层In 2S 3的CZTS太阳能电池表现出最佳的性能，这是由于异质结界面处合适的CBO值以及适当的沉积温度引起的In 2S 3薄膜的晶体质量的改善。在100 °C下制备的器件由于太高的CBO值而表现出最差的性能。结果表明，沉积温度是控制太阳能电池质量的关键参数。
The effect of the deposition temperature of the buffer layer In2S3 on the band alignment of CZTS/In2S3 heterostructures and the solar cell performance have been investigated. The In2S3 films are prepared by thermal evaporation method at temperatures of 30, 100, 150, and 200 °C, respectively. By using x-ray photoelectron spectroscopy (XPS), the valence band offsets (VBO) are determined to be −0.28±0.1 , −0.28±0.1 , −0.34±0.1 , and −0.42±0.1 eV for the CZTS/In2S3 heterostructures deposited at 30, 100, 150, and 200 °C, respectively, and the corresponding conduction band offsets (CBO) are found to be 0.3±0.1 , 0.41±0.1 , 0.22±0.1 , and 0.01±0.1 eV, respectively. The XPS study also reveals that inter-diffusion of In and Cu occurs at the interface of the heterostructures, which is especially serious at 200 °C leading to large amount of interface defects or the formation of CuInS2 phase at the interface. The CZTS solar cell with the buffer layer In2S3 deposited at 150 °C shows the best performance due to the proper CBO value at the heterostructure interface and the improved crystal quality of In2S3 film induced by the appropriate deposition temperature. The device prepared at 100 °C presents the poorest performance owing to too high a value of CBO. It is demonstrated that the deposition temperature is a crucial parameter to control the quality of the solar cells.