Modeling a tandem solar cell based on Sb2S3 and Sb2Se3 absorber layers

Abstract

A device simulation presented for a tandem solar cell of Sb2S3 and Sb2Se3 as top (Eg = 1.7 eV) and bottom (Eg = 1.2 eV) absorber layers. We examined the device characteristics, radiative recombination, and optimum thickness of this tandem cell using filtered spectrum analysis and current-matching techniques in COMSOL. An open-circuit voltage of 1.58 V, current density of 15.50 mA/cm−2, fill factor of 56.90 %, and a remarkable efficiency of 14 %. The optimum thickness of Sb2S3 is 350 nm and for Sb2Se3 is 760 nm. Promising characteristics obtained with a Jsc = 16.32 mA/cm2, Voc = 1.48 V, FF = 60.7 %, and an overall power conversion efficiency of 14.66 %. The optimum acceptor and bulk defect density have been calculated to be NA = 8.9 × 1015 cm−3 and BDD = 7.21 × 10−15 cm−3. The optimized values of radiative recombination rate in Sb2S3 and Sb2Se3 are 0.73 × 10−10 cm3/s and 6.5 × 10−11 cm3/s, respectively.