Lithium-assisted synergistic engineering of charge transport both in GBs and GI for Ag-substituted Cu2ZnSn(S,Se)4 solar cells  

作　　者：Xiangyun Zhao Xiaohuan Chang Dongxing Kou Wenhui Zhou Zhengji Zhou Qingwen Tian Shengjie Yuan Yafang Qi Sixin Wu 

机构地区：[1]The authors contributed equally to this work,Key Lab for Special Functional Materials,Ministry of Education,National&Local Joint Engineering Research Center for High-Efficiency Display and Lighting Technology,School of Materials Science and Engineering,Collaborative Innovation Center of Nano Functional Materials and Applications,Henan University,Kaifeng 475004,Henan,China

出　　处：《Journal of Energy Chemistry》2020年第11期9-15,共7页能源化学（英文版）

基　　金：the National Natural Science Foundation of China(61874159,61974173,51702085,51802081 and 21603058);the Joint Talent Cultivation Funds of NSFC-HN(U1704151);the Science and Technology Innovation Talents in Universities of Henan Province(18HASTIT016)。

摘　　要：Although silver(Ag) substitution offers several benefits in eliminating bulk defects and facilitating interface type inversion for Cu2ZnSn(S,Se)4(CZTSSe) photovoltaic(PV) technology, its further development is still hindered by the fairly low electrical conductivity due to the significant decrease of acceptors amount.In this work, a versatile Li–Ag co-doping strategy is demonstrated to mitigate the poor electrical conductivity arising from Ag through direct incorporating Li via postdeposition treatment(PDT) on top of the Ag-substituted CZTSSe absorber. Depth characterizations demonstrate that Li incorporation increases ptype carrier concentration, improves the carrier collection within the bulk, reduces the defects energy level as well as inverts the electric field polarity at grain boundaries(GBs) for Ag-substituted CZTSSe system. Benefiting from this lithium-assisted complex engineering of electrical performance both in grain interior(GI) and GBs, the power conversion efficiency(PCE) is finally increased from 9.21% to 10.29%. This systematic study represents an effective way to overcome the challenges encountered in Ag substitution,and these findings support a new aspect that the synergistic effects of double cation dopant will further pave the way for the development of high efficiency kesterite PV technology.

关 键 词：Cu2ZnSn(S Se)4 Thin film solar cell Ag substitution Alkali doping POST-TREATMENT 

分 类 号：TB34[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]