Structural and optoelectronic properties of electrodeposited CdSe thin films: Effect of Cu-dopant

Cadmium selenide (CdSe) is a promising semiconductor extensively used in manufacturing optoelectronic devices. Compared to the undoped CdSe (Cu 1), the crystallite size of Cu 2 (1 % at. Cu-doped CdSe) increases from 27 to 29 nm , further Cu-doping into CdSe reduced crystallite size to 5 nm. The absorbance behavior exhibited improvement after Cu-doping. Additionally, the reflectance spectrum of Cu 2 displayed enhancement compared to the Cu 1 attributed to increase in crystallite size. The band gap (Eg) of undoped CdSe was measured at 1.78 eV, showing an increase to 1.89 eV after Cu-doping. Optical conductivity of CdSe samples exhibited an increase following Cu-doping. Consequently, Cu 2 exhibited optimal characteristics for photodetection among all samples, attributed to its higher crystalline quality, lower lattice strain, reduced defect density, and higher carrier concentration. This study reveals the influence of Cu-doping on CdSe, highlighting essential characteristics to enhance its application in optoelectronics.