Restraining the Band Fluctuation of CBD-Zn(O,S) Layer: Modifying the Hetero-Junction Interface for High Performance Cu2ZnSnSe4 Solar Cells With Cd-Free Buffer Layer
Restraining the Band Fluctuation of CBD-Zn(O,S) Layer: Modifying the Hetero-Junction Interface for High Performance Cu2ZnSnSe4 Solar Cells With Cd-Free Buffer Layer
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有机光伏中 TQ1:PC71BM 体异质结电子结构的混合效应
DOI：
10.1002/solr.201700075
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发表时间：
2017-10-01
期刊：
影响因子：
7.9
通讯作者：
Zhang, Yi
中科院分区：
文献类型：
--
作者：
Li, Jianjun;Liu, Xiaoru;Zhang, Yi
Zn(O,S)薄膜是一种很有前景的低成本、环保型无镉缓冲层，适用于黄铜矿和锌黄锡矿薄膜太阳能电池。然而，具有Zn(O,S)缓冲层的器件通常界面性能较差，导致效率低得多，特别是对于黄锌锡矿太阳能电池。在此，Zn(O,S)层中ZnO第二相引起的能带波动被认为是器件性能恶化的主要原因。通过浓氨蚀刻和随后的软退火处理，有害的ZnO和Zn(OH)(2)第二相从Zn(O,S)层中消除，异质结性能显着提高。因此，Zn(O,S)/CZTSe太阳能电池的功率转换效率从1.17%提高到7.2%的有利值。温度相关的 J-V 特性揭示了缺陷水平辅助电荷载流子在 Zn(O,S)/CZTSe 界面上的传输机制。这些令人鼓舞的结果意味着 Zn(O,S) 缓冲层在未来高性能薄膜太阳能电池的制造中有望替代有毒的 CdS。
Zn(O,S) film is a promising low-cost and environment-friendly Cd-free buffer layer for chalcopyrite and kesterite thin film solar cells. However, the devices with Zn(O,S) buffer layer usually suffer from poor interface performance, resulting in a much lower efficiency, especially for kesterite solar cells. Here, the band fluctuation caused by ZnO secondary phase in Zn(O,S) layer is identified as the main reason deteriorating the device performance. By a concentrated ammonium etching and subsequent soft annealing treatment, the detrimental ZnO and Zn(OH)(2) secondary phases are eliminated from the Zn(O,S) layer and the hetero-junction performance is improved significantly. Consequently, the power conversion efficiency of the Zn(O,S)/CZTSe solar cells was improved from 1.17% to a favorable value of 7.2%. Temperature dependent J-V properties reveal a defect level assisted charge carrier transport mechanism across the Zn(O,S)/CZTSe interface. These encouraging results imply that Zn(O,S) buffer layer is a promising substitution for toxic CdS in future manufacturing of high performance thin film solar cells.