Physical Properties of Cu12Sb4S13 Thin Films Deposited at Oblique Incidence by Vacuum Thermal Evaporation

Abstract

The aim of this work is to elaborate and characterize thin films of the Cu12Sb4S13 material which are prepared by vacuum thermal evaporation onto unheated glass substrates at obliquely incident angles (00-85°). We have shown by X-ray diffraction of the Cu12Sb4S13 powder that only the cubic phase is present with the orientation along the (222) plane. The reflection and transmission spectra show the presence of interference fringes which prove the homogeneity of the prepared thin films. The thicknesses of the thin films decrease by increasing the incident angle from 533 to 102 nm. A high absorption coefficient of more than 105 cm-1 was established. The allowed direct transitions increase by increasing the incident angle ranging from 1.42 to 2.49 eV. The electrical measurements show that our thin layer keeps the type of conductivity that is p for the different angles. The resistivity and the concentration of the free charge carriers evolve proportionally with the angles of inclination, while the mobility evolves proportionally opposite which confirms the amorphous appearance.