A high-performance self-powered visible photodetector based on Co-doped Sb2Se3 thin film by electrochemical deposition

Enhancing the electrical properties of Sb 2 Se 3 thin films through elemental doping is a crucial strategy to improve its potential applications in photodetectors. In this study, thin films of Co-doped Sb 2 Se 3 were fabricated through electrochemical deposition. When the doping concentration reached x=0.05, Sb 2 Se 3 thin films were effectively fabricated exhibiting [ hk 1] orientation and a large average grain size. Consequently, the electrical characteristics of the films were improved. Following the incorporation of an Al 2 O 3 barrier layer and CdCl 2 treatment of CdS layer, the photodetector utilizing a thin film of Sb 2 Se 3 with x=0.05 demonstrates a significant response within the visible to near-infrared spectrum under 0 bias conditions. The optimal results were achieved at a wavelength of 635 nm, where the dark current (I dark ) was measured at 5.9 × 10 −7 mA, responsivity (R) at 92 mA/W, detectivity (D*) at 2.11 × 10 12 Jones, and the fitting ideal factor (θ) was determined to be 0.959. The selectivity within the visible wavelength range, coupled with the excellent values of D* and θ, position the device as having significant potential for various applications.