Simulation Driven Insights Into CuGaTe ₂ Based Solar Cells and Photodetectors

In this research, copper gallium telluride (CuGaTe 2 ) (CGT)‐based optoelectronic device is simulated using SCAPS‐1D simulation tool to evaluate its photovoltaic (PV) and photodetector (PD) functionalities. Various materials‐CdS, In 2 S 3 , Zn(O,S), and ZnSe are analyzed as potential window layers, while AgInTe 2 , AlSb, and CuS serve as back surface field (BSF) layers. Throughout the simulation process, the study optimizes structural parameters such as layer thicknesses, doping concentration, and defect densities across the device layers and interfaces. Under optimal design conditions, the device demonstrates outstanding performance, reaching a power conversion efficiency (PCE) of 36.04%, with an open circuit voltage ( V OC ) of 1.12 V, a short circuit current density ( J SC ) of 38.84 mA/cm 2 , and fill factor (FF) of 82.85%. As a PD, the structure achieves a responsivity ( R ) of 0.69 A/W and detectivity () of 4.40 × 10 17 Jones. The peak performances in R and are recorded at a wavelength of 940 nm, with robust detection capabilities maintained across the 800–1000 nm near‐infrared (NIR) range. These finding highlight the significant potential of the CGT‐based device for high‐efficiency applications in NIR photodetection and solar energy conversion.