Yu Xue, Cheng Shuying, Yan Qiong, Yu Jinling, Qiu Wen, Zhou Zhengji, Zheng Qiao, Wu Sixin
College of Physics and Information Engineering, Institute of Micro-Nano Devices and Solar Cells, Fuzhou University Fuzhou 350108 P. R. China
Jiangsu Collaborative Innovation Center of Photovolatic Science and Engineering Changzhou 213164 P. R. China.
RSC Adv. 2018 Aug 3;8(49):27686-27694. doi: 10.1039/c8ra04958k. eCollection 2018 Aug 2.
Cation substitution plays a crucial role in improving the efficiency of CuZnSn(S,Se) (CZTSSe) solar cells. In this work, we report a significant efficiency enhancement of flexible CZTSSe solar cells on Mo foils by partial substitution of Cu with Ag. It is found that the band gap ( ) of (Cu Ag )ZnSn(S,Se) (CAZTSSe) thin films can be adjusted by doping with Ag with from 0 to 6%, and the minimum is achieved with = 5%. We also found that Ag doping can obviously increase the average grain size of the CAZTSSe absorber from 0.4 to 1.1 μm. Additionally, the depletion width ( ) at the heterojunction interface of CAZTSSe/CdS is found to be improved. As a result, the open-circuit voltage deficit ( ) is gradually decreased, and the band tailing is suppressed. Benefiting from the enhanced open-circuit voltage ( ), the power conversion efficiency (PCE) is successfully enhanced from 4.34% ( = 0) to 6.24% ( = 4%), and the decreases from 915 to 848 mV.
阳离子取代在提高铜锌锡硫硒（CZTSSe）太阳能电池的效率方面起着关键作用。在本工作中，我们报道了通过用银部分取代铜，显著提高了钼箔上柔性CZTSSe太阳能电池的效率。研究发现，通过用0%至6%的银掺杂，可以调节（Cu₁₋ₓAgₓ）ZnSn（S,Se）（CAZTSSe）薄膜的带隙（Eg），当x = 5%时可实现最小的Eg。我们还发现，银掺杂可明显将CAZTSSe吸收层的平均晶粒尺寸从0.4μm增加到1.1μm。此外，发现CAZTSSe/CdS异质结界面处的耗尽宽度（Wd）得到改善。结果，开路电压亏损（Voc deficit）逐渐减小，带尾现象得到抑制。受益于开路电压（Voc）的提高，功率转换效率（PCE）成功地从4.34%（x = 0）提高到6.24%（x = 4%），且Voc从915mV降至848mV。
