CIGS solar cells using ZrS2 as buffer layer: Numerical simulation

Abstract

This study presents numerical optimization using the SCAPS-1D software package based on copper indium gallium selenide (CIGS) solar cell structure. ZrS2 is selected as a buffer layer in this research. The effect of carrier concentration and thickness of absorber/buffer layers on the electrical and photovoltaic performance of CIGS/ZrS2 solar cells have been investigated. The results showed an increase in the thickness from 0.2 to 2.0 µm and the carrier concentration of CIGS from 1012 to 1018 cm−3, increasing the Voc. The Jsc was increased with an increase in CIGS thickness. In addition, the increase in carrier concentration and thickness of CIGS lead to an increase in the CIGS/ZrS2 solar cell efficiency. The thickness of 1.4 µm and carrier concertation of 1018 cm−3 have been considered as optimized conditions. The increase in ZrS2 thickness results in an increase in the Jsc, and the power conversion efficiency (η). Consequently, the thickness of 0.35 µm, the carrier concentration of 1017 cm−3, and energy band gap of 1.5 eV can be selected as an optimum conditions for the ZrS2 buffer layer, which presents the η of 26.95%. Finally, the effect of series resistance (Rs) and shunt resistance (Rsh) have been investigated on the CIGS/ZrS2. The results exhibited that optimal solar cell performance is achieved when the Rs is low, and the Rsh is high.