Numerical investigation of a new solar cell structure featuring Ag2GeS3 as the active layer using SCAPS-1D

Abstract

We investigates the high efficiency of a silver germanium sulfide (Ag2GeS3)-based solar cell, a non-toxic and low-cost material, for a novel heterojunction structure, both without and with MoOx hole transport layer (HTL)—(Al:ZnO/CdS/Ag2GeS3/Au) and (Al:ZnO/CdS/Ag2GeS3/MoOxHTL/Au)—using the SCAPS-1D simulator. Al:ZnO is employed as the transparent conductive oxide and cadmium sulfide as the electron transport layer. The incorporation of the MoOx as an electron-blocking HTL dramatically boosts the efficiency from 14% to 26%. This significant gain is attributed to the effective band alignment at the heterojunction interfaces. We also investigate the impact of several factors on the solar cell performance, such as layer thickness, carrier concentration, and the defect density. Furthermore, a density functional theory study is performed to determine the electronic and optical properties of the Ag2GeS3 material required for the simulation. The findings indicate the viability of this design for efficient thin-film solar energy harvesting.