CuGaSe₂ photosensitive devices: a study of reliability and photoresponse with defects

CuGaSe₂(CGSe₂) is the material of choice for future generation photosensitive devices such as solar cells due to its high absorption coefficient and band gap. This material was immediately evaluated to determine its suitability as a photovoltaic material. In this article, this material with the simple structure of ZnO/CdS/CuGaSe₂ was explored using Silvaco TCAD software. The thickness of all layers was optimized to achieve higher efficiency. The maximum achievable efficiency for the device was recorded to be 30.59%, with a current density (J _SC) of 28.03 mA cm^-2, an open circuit voltage (V _OC) of 1.26 V, and a fill factor (FF) of 86.56%. In addition, reliability analysis of the device was carried out using defect simulation to show how it affected the performance. The effect of the defect concentration was evaluated for Gaussian and tail-type distributions. It is interesting to note that the efficiency of the solar cell decreased from 30.59% to below 10% under a worst-case defect simulation.