Synthesis, structure, optical, and electric properties of Ce-doped CuInTe₂ compound

Ce-doped CuInTe₂ (CICT) semiconducting compounds are successfully synthesized. The phase structures, optical, and electric properties are investigated using powder X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), X-ray photoelectron spectrometer (XPS), Raman spectrometer, ultraviolet and visible spectrophotometer (UV-Vis), and a standard four-probe method. CuIn_1-xCe_xTe₂ crystallizes into a tetragonal structure with predominant orientation along the 112 direction. The lattice parameters are a=6.190(6) Å–6.193(0) Å and c=12.406(5) Å–12.409(5) Å. Ce prefers to occupy the 4b crystal position. According to the analysis of XPS spectra, Ce shows the mixture of valences 4+ and 3+. Raman spectra reveal that the photon vibrating model in the CICT follows A₁ mode in a wavenumber range of 123 cm^-1–128 cm^-1. UV-Vis spectra show that the band gap E_g values before and after 0.1 mole Ce doped into CuInTe₂ are 1.28 eV and 1.16 eV, respectively. It might be due to the mixture of valences for Ce. Ce doped into CuInTe₂ still shows the semiconductor characteristics.