DFT studies abided numerical assessment of stable ternary Al2CdX4 (where X = S, Se, Te) chalcogenides for thin film photovoltaics

Abstract

Thin-film solar cells attain excellent performance through the use of thin semiconducting layers that have exceptional light-harvesting capabilities. Although several thin-film solar cells have shown potential, it is still required to look for less expensive and equally promising substitutes. This work highlights the potential use of the low-cost Al2CdX4 chalcogenide as a thin-film photovoltaic light harvester. Using the Cambridge Serial Total Energy Programme (CASTEP), a density functional theory (DFT) software program, the optoelectronic characteristics of Al2CdX4 chalcogenide light harvesters were explored. The Al2CdX4 chalcogenide light harvesters were studied for variations in their density of states (DOS) and bandgap (indirect) tunability. The results obtained were incorporated into the 1D Solar Cell Capacitance Simulator (SCAPS-1D) program to assess the capability of Al2CdX4 chalcogenide solar cells. The power conversion efficiency (PCE) and other properties of the solar cell were primarily dictated by the thickness and density of defects in the Al2CdX4 light harvester. The influence of operating temperature and the work function of metal back contact on solar cell performance are both examined to evaluate the suitability of Al2CdX4-based solar cells for real-time application. Theoretical PCE of ∼29% was obtained in the FTO/AZnO/Al2CdX4/MoO3/rear contact solar cell device structure when thickness and defect density were optimized.