摘要
Cd-free kesterite structured solar cells are currently attracting attention because they are environmentally friendly. It is reported that Zn(O,S) can be used as a buffer layer in these solar cells. However, the band alignment is not clear and the carrier concentration of Zn(O,S) layer is low. In this study, the band alignment of the Zn(O,S)/Cu_2 ZnSnSe_4 p–n junction solar cell and the effect of In_2 S_3/Zn(O,S) double buffer layer are studied by numerically simulation with wxAMPS software.By optimizing the band gap structure between Zn(O,S) buffer layer and Cu_2 ZnSnSe_4 absorber layer and enhancing the carrier concentration of Zn(O,S) layer, the device efficiency can be improved greatly. The value of CBO is in a range of 0 eV–0.4 eV for S/(S + O)= 0.6–0.8 in Zn(O,S). The In_2 S_3 is mainly used to increase the carrier concentration when it is used as a buffer layer together with Zn(O,S).
Cd-free kesterite structured solar cells are currently attracting attention because they are environmentally friendly. It is reported that Zn(O,S) can be used as a buffer layer in these solar cells. However, the band alignment is not clear and the carrier concentration of Zn(O,S) layer is low. In this study, the band alignment of the Zn(O,S)/Cu_2 ZnSnSe_4 p–n junction solar cell and the effect of In_2 S_3/Zn(O,S) double buffer layer are studied by numerically simulation with wxAMPS software.By optimizing the band gap structure between Zn(O,S) buffer layer and Cu_2 ZnSnSe_4 absorber layer and enhancing the carrier concentration of Zn(O,S) layer, the device efficiency can be improved greatly. The value of CBO is in a range of 0 eV–0.4 eV for S/(S + O)= 0.6–0.8 in Zn(O,S). The In_2 S_3 is mainly used to increase the carrier concentration when it is used as a buffer layer together with Zn(O,S).
基金
Project supported by the National Natural Science Foundation of China(Grant Nos.51572132,61674082,and 61774089)
the National Key Research and Development Program of China(Grant No.2018YFB1500202)
the Tianjin Natural Science Foundation of Key Project of China(Grant Nos.16JCZDJC30700and 18JCZDJC31200)
the 111 Project,China(Grant No.B16027)
