Highly efficient solution-processed CZTSSe solar cells based on a convenient sodium-incorporated post-treatment method  

作　　者：Biwen Duan Linbao Guo Qing Yu Jiangjian Shi Huijue Wu Yanhong Luo Dongmei Li Sixin Wu Zhi Zheng Qingbo Meng 

机构地区：[1]Key Laboratory for Renewable Energy(CAS),Beijing Key Laboratory for New Energy Materials and Devices,Institute of Physics,Chinese Academy of Sciences,Beijing 100190,China [2]Center of Materials Science and Optoelectronics Engineering,University of Chinese Academy of Sciences,Beijing 100049,China [3]School of Physical Sciences,University of Chinese Academy of Sciences,Beijing 100049,China [4]Songshan Lake Materials Laboratory,Dongguan 523808,Guangdong,China [5]Key Laboratory for Special Functional Materials of MOE,Henan University,Kaifeng 475004,Henan,China [6]Key Laboratory for Miao-Nano Energy Storage and Conversion Materials of Henan Province,College of Advanced Materials and Energy,Institute of Surface Micro and Nanomaterials,Xuchang University,Xuchang 461000,Henan,China

出　　处：《Journal of Energy Chemistry》2020年第1期196-203,I0007,共9页能源化学（英文版）

基　　金：financially supported by the National Natural Science Foundation of China (Nos. 51421002, 51627803, 91733301, 51761145042, 21501183, 51402348, 53872321, and 11874402);the Knowledge Innovation Program and the Strategic Priority Research Program (Grant XDB 12010400) of the Chinese Academy of Sciences

摘　　要：In CZTSSe solar cells,a simple sodium-incorporation post-treatment method toward solution-processed Cu2Zn Sn S4precursor films is presented in this work.An ultrathin NaCl film is deposited on Cu2Zn Sn S4precursor films by spin-coating NaCl solution.In subsequent selenization process,the introduction of Na Cl is found to be benefacial for the formation of Cu2-xSe,which can further facilitate the element transportation,leading to dense and smooth CZTSSe films with large grains and less impurity Cu2Sn(S,Se)3phase.SIMS depth profiles confirm the gradient distribution of the sodium element in Na-doped absorbers.Photoluminescence spectra show that the introduction of appropriate sodium into the absorber can inhibit the band tail states.As high as 11.18% of power conversion efficiency(PCE)is achieved for the device treated with 5 mg mL^-1 NaCl solution,and an average efficiency of Na-doped devices is 10.71%,13%higher than that of the control groups(9.45%).Besides,the depletion width and the charge recombination lifetime can also have regular variation with sodium treatment.This work offers an easy modification method for high-quality Na-doped CZTSSe films and high-performance devices,in the meantime,it can also help to further understand the effects of sodium in CZTSSe solar cells.In CZTSSe solar cells,a simple sodium-incorporation post-treatment method toward solution-processed Cu2Zn Sn S4precursor films is presented in this work.An ultrathin Na Cl film is deposited on Cu2Zn Sn S4precursor films by spin-coating Na Cl solution.In subsequent selenization process,the introduction of Na Cl is found to be benefacial for the formation of Cu2-xSe,which can further facilitate the element transportation,leading to dense and smooth CZTSSe films with large grains and less impurity Cu2Sn（S,Se）3phase.SIMS depth profiles confirm the gradient distribution of the sodium element in Na-doped absorbers.Photoluminescence spectra show that the introduction of appropriate sodium into the absorber can inhibit the band tail states.As high as 11.18%of power conversion efficiency（PCE）is achieved for the device treated with 5 mg m L-1Na Cl solution,and an average efficiency of Na-doped devices is 10.71%,13%higher than that of the control groups（9.45%）.Besides,the depletion width and the charge recombination lifetime can also have regular variation with sodium treatment.This work offers an easy modification method for high-quality Na-doped CZTSSe films and high-performance devices,in the meantime,it can also help to further understand the effects of sodium in CZTSSe solar cells.

关 键 词：Thin film solar cell CZTSSe Sodium doping POST-TREATMENT Spin-coating method 

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