Numerical Simulation of Thin Film Solar Cell Using SCAPS-1D: ZnSe as Window Layer

Abstract

Investigation on properties of Copper-Indium-GalliumSelenide (CIGS) based solar cells has been numerically performed by Scaps-1D. Designing ZnSe/CdS/OVC/CIGS structure, we have extracted current-voltage relation, quantum efficiency, cells efficiency etc. and also evaluated the effect of thickness for both absorber (CIGS) and window (ZnSe) layer on cells performance like short circuit current (I sc ), open circuit voltage (V oc ), fill factor, quantum and cells efficiency. We varied thickness of absorber layer from 0.2 μm to 1.0 μm and window layer from 30 nm to 90 nm and our simulation results showed that cells parameters are significantly affected by both absorber and window layer thickness. Like as the thickness of absorber layer increases, current density as well as cells efficiency enhances which is just reverse for ZnSe window layer thickness. We got maximum 21.47% cells efficiency for 30 nm ZnSe window layer and 22.86% for 1 μm CIGS layer and minimum 18.52% and 17.03% for 90 nm ZnSe and 0.2 μm CIGS layer respectively. Effect of these two layers on quantum efficiency is also significant with thickness variation. A thin layer of MgF 2 having thickness of 10 nm is used as antireflection coating over window layer to accelerate internal absorption and Mo and Al are utilized as back and front contact respectively.