Analysis of the open-circuit voltage of Cu2ZnSn(S, Se)4 thin film solar cell
Analysis of the open-circuit voltage of Cu2ZnSn(S, Se)4 thin film solar cell
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DOI：
10.1016/j.solener.2018.02.066
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发表时间：
2018-04
期刊：
影响因子：
6.7
通讯作者：
Xu Jiaxiong;Lin Junhui;Zhuang Chunan
中科院分区：
文献类型：
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作者：
Xu Jiaxiong;Lin Junhui;Zhuang Chunan
目前，Cu2ZnSn(S, Se)4（CZTSSe）薄膜太阳能电池的转换效率主要受其开路电压低的限制。本文利用模拟程序AFORS-HET v2.5对CZTSSe薄膜太阳能电池的性能进行了计算，揭示了提高开路电压的一些有用方法。首先，分析了影响开路电压的几个因素。通过降低缺陷态、界面态、寄生电阻效应和mos2层的形成，以及调整CZTSSe吸收体的空穴浓度或带隙，可以显著提高CZTSSe太阳能电池的开路电压。然后，在CZTSSe吸收器中引入带隙梯度，扩大内置电场，增强吸收，从而对CZTSSe太阳能电池的开路电压产生良性影响。最后，考虑了CZTSSe太阳能电池的后表面场。CZTSSe和非晶硅背表面电场的影响取决于缺陷状态。当缺陷密度较低时，后表面场的优势更为突出。在考虑后表面场之前，有必要减少缺陷。在计算中，最好的CZTSSe太阳能电池的开路电压亏缺仅为0.134 V。本文的数值分析为提高CZTSSe薄膜太阳能电池的开路电压和转换效率提供了一些方法。提出的方法对实验工作具有指导意义。
Currently, the conversion efficiency of Cu2ZnSn(S, Se)4(CZTSSe) thin film solar cell is mainly limited by its low open-circuit voltage. In this work, the performances of CZTSSe thin film solar cell were calculated by the simulation program AFORS-HET v2.5 to reveal some useful ways to enhance the open-circuit voltage. First, several factors affecting the open-circuit voltage were analyzed. The open-circuit voltage of CZTSSe solar cell was significantly improved by reducing the defect states, interface states, parasitic resistance effect, and formation of MoS2layer, and adjusting the hole concentration or band gap of CZTSSe absorber. Then, the band gap gradient was introduced into the CZTSSe absorber to extend the built-in electric field and enhance absorptions, leading to benign impacts on the open-circuit voltage of CZTSSe solar cell. Finally, a back surface field was considered for the CZTSSe solar cell. The effects of CZTSSe and amorphous silicon back surface fields depended on the defect states. The advantage of back surface field was prominent when the defect density was low. It was necessary to reduce the defects before considering a back surface field. In the calculations, the best CZTSSe solar cell had an open-circuit voltage deficit of only 0.134 V. The numerical analyses in this work provide some methods to improve the open-circuit voltage and conversion efficiency CZTSSe thin film solar cell. The proposed methods offer guidance for experimental works.