title: Sulfurization induced surface constitution and its correlation to the performance of solution-processed Cu2ZnSn(S,Se)4 solar cells.
abstract: To obtain high photovoltaic performances for the emerging copper zinc tin sulfide/selenide (CZTSSe) thin film solar cells, much effort has deservedly been placed on CZTSSe phase purification and CZTSSe grain size enhancement. Another highly crucial but less explored factor for device performance is the elemental constitution of CZTSSe surface, which is at the heart of p-n junction where major photogenerated carriers generate and separate. In this work we demonstrate that, despite the well-built phase and large grained films are observed by common phases and morphology characterization (XRD, Raman and SEM), prominent device efficiency variations from short circuited to 6.4% are obtained. Insight study highlights that the surface (0-250 nm) compositions variation results in different bulk defect depths and doping densities in the depletion zone. We propose that suitable sulfurization (at ~ 10 kPa sulfur pressure) drives optimization of surface constitution by managing the Cu, Zn and Sn diffusion and surface reaction. Therefore, our study reveals that the balance of elemental diffusion and interface reactions is the key to tuning the surface quality CZTSSe film and thus the performance of as resulted devices.
authors.affiliation: 1] Wuhan National Laboratory for Optoelectronics (WNLO) [2] School of Optical and Electronic Information, Huazhong University of Science and Technology (HUST), Wuhan, 430074, China.
authors.forename: Jie
authors.initials: J
authors.lastname: Zhong
authors.affiliation: 1] Wuhan National Laboratory for Optoelectronics (WNLO) [2] School of Optical and Electronic Information, Huazhong University of Science and Technology (HUST), Wuhan, 430074, China.
authors.forename: Zhe
authors.initials: Z
authors.lastname: Xia
authors.affiliation: 1] Wuhan National Laboratory for Optoelectronics (WNLO) [2] School of Optical and Electronic Information, Huazhong University of Science and Technology (HUST), Wuhan, 430074, China.
authors.forename: Miao
authors.initials: M
authors.lastname: Luo
authors.affiliation: Department of Materials Engineering, Monash University, VIC 3800 Australia.
authors.forename: Juan
authors.initials: J
authors.lastname: Zhao
authors.affiliation: 1] Wuhan National Laboratory for Optoelectronics (WNLO) [2] School of Optical and Electronic Information, Huazhong University of Science and Technology (HUST), Wuhan, 430074, China.
authors.forename: Jie
authors.initials: J
authors.lastname: Chen
authors.affiliation: 1] Wuhan National Laboratory for Optoelectronics (WNLO) [2] School of Optical and Electronic Information, Huazhong University of Science and Technology (HUST), Wuhan, 430074, China.
authors.forename: Liang
authors.initials: L
authors.lastname: Wang
authors.affiliation: 1] Wuhan National Laboratory for Optoelectronics (WNLO) [2] School of Optical and Electronic Information, Huazhong University of Science and Technology (HUST), Wuhan, 430074, China.
authors.forename: Xinsheng
authors.initials: X
authors.lastname: Liu
authors.affiliation: 1] Wuhan National Laboratory for Optoelectronics (WNLO) [2] School of Optical and Electronic Information, Huazhong University of Science and Technology (HUST), Wuhan, 430074, China.
authors.forename: Ding-Jiang
authors.initials: DJ
authors.lastname: Xue
authors.affiliation: 1] Wuhan National Laboratory for Optoelectronics (WNLO) [2] Department of Materials Engineering, Monash University, VIC 3800 Australia.
authors.forename: Yi-Bing
authors.initials: YB
authors.lastname: Cheng
authors.affiliation: 1] Wuhan National Laboratory for Optoelectronics (WNLO) [2] School of Optical and Electronic Information, Huazhong University of Science and Technology (HUST), Wuhan, 430074, China.
authors.forename: Haisheng
authors.initials: H
authors.lastname: Song
authors.affiliation: 1] Wuhan National Laboratory for Optoelectronics (WNLO) [2] School of Optical and Electronic Information, Huazhong University of Science and Technology (HUST), Wuhan, 430074, China.
authors.forename: Jiang
authors.initials: J
authors.lastname: Tang