中国物理B ›› 2017, Vol. 26 ›› Issue (4): 46802-046802.doi: 10.1088/1674-1056/26/4/046802

• CONDENSED MATTER: STRUCTURAL, MECHANICAL, AND THERMAL PROPERTIES • 上一篇    下一篇

Effect of deposited temperatures of the buffer layer on the band offset of CZTS/In2S3 heterostructure and its solar cell performance

Jinling Yu(俞金玲), Zhongming Zheng(郑重明), Limei Dong(董丽美), Shuying Cheng(程树英), Yunfeng Lai(赖云锋), Qiao Zheng(郑巧), Haifang Zhou(周海芳), Hongjie Jia(贾宏杰), Hong Zhang(张红)   

  1. 1 Institute of Micro/Nano Devices and Solar Cells, School of Physics and Information Engineering, Fuzhou University, Fuzhou 350108, China;
    2 Jiangsu Collaborative Innovation Center of Photovolatic, Science and Engineering, Changzhou University, Changzhou 213164, China
  • 收稿日期:2011-01-01 修回日期:2017-02-03 出版日期:2017-04-05 发布日期:2017-04-05
  • 通讯作者: Shuying Cheng E-mail:sycheng@fzu.edu.cn
  • 基金资助:
    Project supported by the National Natural Science Foundation of China (Grant Nos. 61574038 and 61674038) and the Natural Science Foundation of Fujian Province, China (Grant No. 2014J05073).

Effect of deposited temperatures of the buffer layer on the band offset of CZTS/In2S3 heterostructure and its solar cell performance

Jinling Yu(俞金玲)1,2, Zhongming Zheng(郑重明)1, Limei Dong(董丽美)1, Shuying Cheng(程树英)1,2, Yunfeng Lai(赖云锋)1, Qiao Zheng(郑巧)1, Haifang Zhou(周海芳)1, Hongjie Jia(贾宏杰)1, Hong Zhang(张红)1   

  1. 1 Institute of Micro/Nano Devices and Solar Cells, School of Physics and Information Engineering, Fuzhou University, Fuzhou 350108, China;
    2 Jiangsu Collaborative Innovation Center of Photovolatic, Science and Engineering, Changzhou University, Changzhou 213164, China
  • Received:2011-01-01 Revised:2017-02-03 Online:2017-04-05 Published:2017-04-05
  • Contact: Shuying Cheng E-mail:sycheng@fzu.edu.cn
  • Supported by:
    Project supported by the National Natural Science Foundation of China (Grant Nos. 61574038 and 61674038) and the Natural Science Foundation of Fujian Province, China (Grant No. 2014J05073).

摘要: 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℃, 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℃, 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℃ 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℃ 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℃ 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.

关键词: band offset, deposition temperature, CZTS/In2S3 heterostructure, solar cell

Abstract: 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℃, 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℃, 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℃ 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℃ 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℃ 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.

Key words: band offset, deposition temperature, CZTS/In2S3 heterostructure, solar cell

中图分类号:  (Semiconductors)

  • 68.55.ag
68.35.Fx (Diffusion; interface formation) 73.50.Pz (Photoconduction and photovoltaic effects)