Space-charge-limited current activation in self-powered and solar-range nanostructured Cu3Se2 photodetector by Zn concentrations

In this research, the impact of the different zinc (Zn) concentrations on the physical and optoelectronic properties of copper selenide (Cu3Se2) nanostructures as self-powered and solar-range photodetector applications was investigated. The obtained results indicated the formation of a tetragonal Cu3Se2 phase with a spherical-like morphology. All the samples showed Cu-poor stoichiometry, and the incorporation of the Zn atoms in the Cu3Se2 lattice decreased the optical energy band gap. It was observed that Zn concentrations activated the space charge-limited conduction (SCLC) mechanism in the Cu3Se2 devices. The band alignments and barrier potentials at different interfaces were studied for understanding the observed transportation mechanism. Finally, it was found that the Zn-doped sample with the highest amount of Zn concentration showed the highest values of the responsivity (R), gain (G), and specific detectivity (D*) in the amounts of 0.127 mA/W, 21.77%, and 3.92 x 10+8 Jones, respectively.