Micro-mechanism study of the effect of Cd-free buffer layers ZnxO(x = Mg/Sn) on the performance of flexible Cu2ZnSn(S, Se)4 solar cell  

作　　者：张彩霞 李雅玲 林蓓蓓 唐建龙 孙全震 谢暐昊 邓辉 郑巧 程树英 Caixia Zhang;Yaling Li;Beibei Lin;Jianlong Tang;Quanzhen Sun;Weihao Xie;Hui Deng;Qiao Zheng;Shuying Cheng(College of Physics and Information Engineering,and Institute of Micro-Nano Devices and Solar Clls,Fuzhou University,Fuzhou 350108,China;Jiangsu Collborative Innovation Center of Photovoltaic Science and Engineering,Changzhou 213164,China)

机构地区：[1]College of Physics and Information Engineering,and Institute of Micro-Nano Devices and Solar Cells,Fuzhou University,Fuzhou 350108,China [2]Jiangsu Collaborative Innovation Center of Photovoltaic Science and Engineering,Changzhou 213164,China

出　　处：《Chinese Physics B》2023年第2期555-566,共12页中国物理B（英文版）

基　　金：supported by the National Natural Science Foundation of China (Grant Nos. 62074037 and 52002073);the Fund from the Fujian Science & Technology Innovation Laboratory for Optoelectronic Information of China (Grant No. 2021ZZ124)。

摘　　要：The traditional CdS buffer layers in flexible CZTSSe solar cells lead to light absorption losses and environmental pollution problems. Therefore, the study of Cd-free buffer layer is very important for the realization of environmentally friendly and efficient CZTSSe solar cells. The Zn1-xMgxO(ZnMgO) and Zn1-xSnxO(ZnSnO) alternate buffer layers are studied in this study using the simulation package solar cell capacitance simulator(SCAPS-1D) numerical simulation model, and the theoretical analysis is further verified by the results of the experiments. We simulate the performance of CZTSSe/ZnXO(X = Mg/Sn) heterojunction devices with different Mg/(Zn+Mg) and Sn/(Zn+Sn) ratios and analyze the intrinsic mechanism of the effect of conduction band offsets(CBO) on the device performance. The simulation results show that the CZTSSe/ZnXO(X = Mg/Sn) devices achieve optimal performance with a small “spike” band or “flat” band at Mg and Sn doping concentrations of 0.1 and 0.2, respectively. To investigate the potential of Zn_(0.9)Mg_(0.1O) and Zn_(0.8)Sn_(0.2)O as alternative buffer layers, carrier concentrations and thicknesses are analyzed. The simulation demonstrates that the Zn0.9Mg0.1O device with low carrier concentration has a high resistivity, serious carrier recombination, and a greater impact on performance from thickness variation. Numerical simulations and experimental results show the potential of the ZnSnO buffer layer as an alternative to toxic CdS, and the ZnMgO layer has the limitation as a substitute buffer layer. This paper provides the theoretical basis and experimental proof for further searching for a suitable flexible CZTSSe Cd-free buffer layer.

关 键 词：ZnMgO/ZnSnO numerical simulation Cd-free buffer heterojunction interface 

分 类 号：TM914.4[电气工程—电力电子与电力传动] TQ132.41[化学工程—无机化工]