High Efficiency CuInS_2 Thin Film Solar Cells

高效率CuInS_2薄膜太阳能电池

• 批准号: 11450137
• 负责人: ITO Kentaro
• 金额: $ 6.14万
• 依托单位: Shinshu University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (B)
• 财政年份: 1999
• 资助国家: 日本
• 起止时间: 1999 至 2001
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-11450137/
• 关键词: solar cell; compound semiconductor; thin film; CuInS_2; Ga添加; Na添加; Zn化合物バッファー層; 伝導帯の不連続; 硫化物薄膜; カルコパイライト型化合物; ヘテロ接合太陽電池; 光電変換効率; 容量-電圧特性; 電流-電圧特性; 分光学的光応答; dead layer

A 12.25 % efficiency solar cell has been achieved using the CuInS_2 thin film as an optical absorber layer produced by a sequential process that is advantageous to mass production of large area cells. Here we added a small amount of Ga to a metallic precursor and then sulfurized it by rapid thermal process to obtain a flat absorber layer with good crystallinity.The diode factor and the dark current density of a heterojunction was decreased by using a composite buffer layer which consists of a very thin Zn compound layer sandwiched between a CdS buffer layer and an absorber layer. The efficiency of the cell was thus improved to 12.1 %.In the heterojunction consisting of chemical bath deposited Zn( S, O, OH ) and In( S, O, OH ) thin buffer layer instead of toxic CdS, we observed conduction band offsets of 0.4 eV ( energy cliff ) and 0.8 eV ( energy spike ), respectively. The solar cell with the former ( latter ) heterojunction exhibited a 7 % ( 10.1 % ) efficiency. In the former ( latter ) case, we needed annealing of the heterojunction ( surface treatment of the absorber surface by an iodide solution ).The various characteristics of the thin film solar cell such as capacitance-voltage curve, current-voltage curve and spectral photoresponse could be explained by a theretical device model, where we assume the existence of a thin n-type CulnS_2 layer at the heterointerface. The experimental finding that the open-circuit voltage increases with decreasing the electric field at the junction agreed fairly well with the theoretical expectation.

采用顺序工艺制备的CuInS_2薄膜作为光吸收层，获得了12.25%的太阳能电池效率，有利于大面积电池的批量生产。在金属前体中加入少量Ga，然后通过快速热处理使其硫化，得到结晶性良好的平坦吸收层，并通过在CdS缓冲层和吸收层之间夹入一层很薄的Zn化合物层，降低了异质结的二极管因子和暗电流密度。在化学浴沉积Zn（S，O，OH）和In（S，O，OH）薄缓冲层代替有毒的CdS组成的异质结中，我们观察到导带偏移分别为0.4eV（能量悬崖）和0.8eV（能量尖峰）。具有前（后）异质结的太阳能电池表现出7%（10.1%）的效率。在前（后）种情况下，我们需要对异质结进行退火（用碘化物溶液对吸收体表面进行表面处理），薄膜太阳能电池的各种特性，如电容-电压曲线、电流-电压曲线和光谱光响应，都可以用一个理论的器件模型来解释，其中假设在异质结界面处存在一个薄的n型CuInS_2层。开路电压随结处电场的减小而增大的实验结果与理论预期相当吻合。

项目成果

Ichino,K. et al: "Optimization of fabrication processes for a Cu( In, Ga )S_2 thin film solar cell"Proc. 16th European Photovoltaic Solar Energy Conference. 717-720 (2000)

一野，K.

Ito,K. ef al: "Cu-rich process of CuInS_2 solar cells"Proc. of the second Magneto-Electronics International Symposium. 133-136 (1999)

没关系。

K.Okamoto: "CuInS_2 Thin Film Solar Cell Prepared by Optimized Cd-Free Process"To be published in the Proceedings of the 17-<th> European Photovoltaic Solar Energy Conference.

K.Okamoto：“通过优化的无镉工艺制备的CuInS_2薄膜太阳能电池”将发表在第17届欧洲光伏太阳能会议的会议记录上。

Ito,K. et al: ""CuInS_2 Thin Film Solar Cells" in Japanese Research Review for Pioneering Ternary and Multinary Compounds in the 21st century"IPAP Books. 1. 342-347 (2001)

没关系。

K.Ichino et al.: "Optimization of fabrication processes for a Cu(In, Ga)S_2 thin film solar cell"Proc. 16^<th> European Photovoltaic Solar Energy Conference, pp 717-720,2000. 717-720 (2000)

K.Ichino 等人：“Cu(In, Ga)S_2 薄膜太阳能电池制造工艺的优化”Proc.