Enhancing CIGS Solar Cell Performance with Erbium-Doped TiO2 Nanomaterial: Simulation Study

Abstract

Objectives: To find a proper rare earth-doped metal-oxide-based buffer layer for CIGS solar cells with improved performance that has less harmfulness than cadmium. Methods: This study concentrated on the synthesis of pure and Erdoped TiO 2 nanomaterials via microwave-assisted hydrothermal method and its characterization results. Additionally, to analyze the performance of TiO 2 and Er-doped TiO 2 as a buffer layer in a CIGS solar cell, numerical simulations were performed using the SCAPS-1D (Solar cell capacitance simulator) software. Findings: The positive outcomes came from the characterization results, which revealed that the synthesized nanomaterials have an anatase phase, microscopic crystallite size, and flower-like shape. The band gap effectively decreases from 3.45 eV for pure TiO 2 to 2.75 eV for Er-doped TiO 2 , which effectively increases the absorption in the visible portion of the solar spectrum. The refractive indices of pure and Er-doped TiO 2 were calculated as 2.37 and 2.50 respectively from their corresponding band gaps. The results from the simulations showed that using a single buffer layer of Er-doped TiO 2 uplifted the performance of the CIGS solar cell, resulting in higher open circuit voltage, increased short-circuit current density with overall efficiency, η = 25.31% compared to pure TiO 2 and CdS-based dual buffer layers. Novelty: For the first time, the Er-TiO 2 nanomaterial was studied as buffer layer material. The numerical simulation and characterization findings justify the adoption of Er-TiO 2 as a buffer layer in CIGS solar cells.