Na-doping-induced modification of the Cu_(2)ZnSn(S,Se)_(4)/CdS heterojunction towards efficient solar cells  

作　　者：Yali Sun Hongling Guo Pengfei Qiu Shengli Zhang Siyu Wang Li Wu Jianping Ao Yi Zhang 

机构地区：[1]Institute of Photoelectronic Thin Film Devices and Technology and Tianjin Key Laboratory of Thin Film Devices and Technology,Nankai University,Tianjin 300350,China [2]College of Physics Science and Technology,Hebei University,Baoding 071002,Hebei,China [3]The MOE Key Laboratory of Weak-Light Nonlinear Photonics,School of Physics,Nankai University,Tianjin 300071,China

出　　处：《Journal of Energy Chemistry》2021年第6期618-626,I0015,共10页能源化学（英文版）

基　　金：supported by the National Key R&D Program of China(2019YFB1503500,2018YFB1500200,2018YEE0203400);the Natural Science Foundation of China(U1902218,11774187);the 111 project(B16027)。

摘　　要：It is very important to understand why a small amount of alkali metal doping in Cu_(2)ZnSn(S,Se)_(4)(CZTSSe)solar cells can improve the conversion efficiency.In this work,Na-doped CZTSSe is prepared by a simple solution method,and then the effects on the surface properties of the absorber layer,the buffer layer growth,and the modifications of the solar cell performance induced by the Na doping are studied.The surface of the absorber layer is more Cu-depletion and less roughness due to the Na doping.In addition,the contact angle of the surface increases because of Na doping.As a consequence,the thickness of the CdS buffer layer is significantly reduced and the optical losses in the CdS buffer layer are decreased.The difference of quasi-Fermi levels(EFn-EFp) increases with a small amount of Na doping in the CZTSSe solar cell,so that open circuit voltage(VOC) increased significantly.This work offers new insights into the effects of Na doping on CZTSSe via a solution-based approach and provides a deeper understanding of the origin of the efficiency improvement of Na-doped CZTSSe thin film solar cells.

关 键 词：Cu_(2)ZnSn(S Se)_(4)solar cells Na doping HETEROJUNCTION Contact angles Simulation analysis 

分 类 号：TM914.4[电气工程—电力电子与电力传动] TB383.2[一般工业技术—材料科学与工程]