Cu2ZnSnS4 photovoltaic cell with improved efficiency fabricated by high-temperature annealing after CdS buffer-layer deposition

摘要

To improve the photovoltaic properties of Cu2ZnSnS4 (CZTS) cells, we investigated the effect of both the thickness of the deposited CdS layers and the post-annealing temperature following CdS deposition on the photovoltaic properties of CZTS cells using a two-layer CZTS structure. By depositing a thin CdS layer (40nm) followed by high temperature annealing (603K), we observed a remarkable increase in the short-circuit current density because of the enhancement of the external quantum efficiency in the wavelength range of 400-800nm. The best CZTS cell exhibited a conversion efficiency of 9.4% in the active area (9.1% in the designated area). In addition, we also fabricated a CZTS cell with open-circuit voltage of 0.80V by appropriately tuning the composition of the CZTS layers. Copyright (c) 2016 John Wiley & Sons, Ltd.