Influencing Mechanism of the Selenization Temperature and Time on the Power Conversion Efficiency of Cu₂ZnSn(S,Se)₄-Based Solar Cells

Abstract

Cu2ZnSn(S,Se)4 (CZTSSe) films were deposited on the Mo-coated glass substrates, and the CZTSSe-based solar cells were successfully fabricated by a facile solution method and postselenization technique. The influencing mechanisms of the selenization temperature and time on the power conversion efficiency (PCE), short-circuit current density (Jsc), open-circuit voltage (Voc), and fill factor (FF) of the solar cell are systematically investigated by studying the change of the shunt conductance (Gsh), series resistance (Rs), diode ideal factor (n), and reversion saturation current density (J0) with structure and crystal quality of the CZTSSe film and CZTSSe/Mo interface selenized at various temperatures and times. It is found that a Mo(S1-x,Sex)2 (MSSe) layer with hexagonal structure exists at the CZTSSe/Mo interface at the temperature of 500 °C, and its thickness increases with increasing selenization temperature and time. The MSSe has a smaller effect on the Rs, but it has a larger influence on the Gsh, n, and J0. The PCE, Voc, and FF change dominantly with Gsh, n, and J0, while Jsc changes with Rs and Gsh, but not Rs. These results suggest that the effect of the selenization temperature and time on the PCE is dominantly contributed to the change of the CZTSSe/CdS p-n junction and CZTSSe/MSSe interface induced by variation of the quality of the CZTSSe film and thickness of MSSe in the selenization process. By optimizing the selenization temperature and time, the highest PCE of 7.48% is obtained.

Enhanced efficiency of Cu2ZnSn(S,Se)4 solar cells via anti-reflectance properties and surface passivation by atomic layer deposited aluminum oxide

“…Kesterite Cu 2 ZnSn(S,Se) 4 (CZTSSe) has attracted much more attention as a promising substitute for CIGS solar cells on account of its outstanding optoelectronic properties and earth abundant, as well as nontoxic, constituents.…”

“…3, 4 The kesterite structure of CZTSSe is derived from the chalcopyrite crystal structure of CIGS, where Zn 2+ and Sn 4+ ions replace an equal number of In 3+ and Ga…”

Multifunctional Copper‐Based Quaternary Chalcogenide Semiconductors Toward State‐of‐the‐Art Energy Applications

“…Moreover, the solution processed nanocrystal approach emphasizes the ease of device fabrication and cost minimization ,,. Also, the chalcogenization yields better efficiency by enhancing the electron transport and optical properties of the material ,,…”

Impact of Antisite Defect Complex on Optical and Electrical Properties of Ag2ZnSnSe4 Thin Films

“…Despite the aforementioned merits, AZTSe material was less explored in the aspects of fundamental properties. Therefore, it is necessary to put efforts in the detailed understanding of fundamental properties tending toward the development of high‐quality AZTSe thin films with better crystallinity, morphology, and optoelectronics properties to further improve PCEs.…”

“…In the two‐step method, high‐temperature selenization ( T Se ) is one of the important process parameters, which severely affects the quality of chalcogenide films, if not properly chosen and controlled. Further, the selenization at elevated temperature results in the re‐evaporation of volatile tin and selenium elements, yielding to low‐quality chalcogenides films with the segregation of ZnSe at the surface . Therefore, in this work, a systematic study has been conducted to prepare AZTSe thin films using the two‐step method, precisely manifesting the impact of selenization temperature on the growth mechanism for obtaining single phase, and discuss the role of antisite defect complex on the optical and electrical properties of AZTSe thin films.…”