Copper(I) Selenide Thin Films: Composition, Morphology, Structure, and Optical Properties

The systematized results of studies of the composition, morphology, structure, optical properties, and conductivity of hydrochemically deposited copper(I) selenide thin films (Cu_1.8Se) with the thickness of 390–400 nm are reported. The studies are carried out using scanning electron microscopy, energy-dispersive analysis, X-ray diffraction analysis, and X-ray photoelectron spectroscopy. The hole conductivity of the layers is established by the thermopower technique. The optical band gap determined from the results of studies of optical absorbance and diffuse reflection spectra of the films at 298 K is 2.5 and 1.84 eV for direct and indirect optical transitions, respectively.