Investigation of the Influence of Variations in Thickness and Concentration on the Optoelectronic Characteristics of p-CuI/n-InSe Photodetector

The SCAPS-1D software was used to simulate a p–CuI/n–InSe photodetector at 300 K with AM1.5G light. The simulation results showed that, with a quantum efficiency of 97.6% at 800 nm and a responsivity of 0.67 A/W, the ideal absorber layer thickness of 0.8 µm produced the highest overall performance. The specific detectivity was enhanced to 2.5 × 1015 cm·Hz1 / 2 ·W−3 and the dark current was decreased by increasing the InSe carrier concentration from 1 × 1015 cm−3 to 3 × 1015 cm−3 . These findings show that the CuI/InSe heterojunction’s broadband response, strong responsivity, and low dark current make it a viable option for near-infrared photodetection applications.