Structural and electronic properties of (CdTe)(1-x)(In2Te3)(x) films grownby close-spaced vapor transport combined with free evaporation

The structural and electronic properties of (CdTe)(1-x)(In2Te3)(x) thin fil ms as a function of substrate temperature were studied using x-ray diffract ion, energy dispersive x-ray analysis, and Raman, transmission, and modulat ed transmission spectroscopies. The films were grown by the close-spaced va por transport technique combined with free evaporation; CdTe and In2Te3 wer e used as sources. From x-ray diffraction the presence of mixed phases and differences in composition were detected, and good correlation with Raman s pectroscopy was found. Transmission spectroscopy suggested the possibility of a modulation of the band gap of the alloy from a value as low as 0.5 eV up to 1.5 eV, Single-phase films presented a direct band gap of around 1.15 eV, as obtained from modulated transmission measurements.