Strucural and Electrical Properties of Cu_2SeTe Thin Films

摘要

Cu_2SeTe compound semiconductor thin films were prepared by Resistive heating under high vacuum 10~(-6) ton. High pure (99.999%) Cu, Se and Te elements were taken in stoichiometric proportions to prepare the bulk powder. The films of different thicknesses were deposited on as cleaved mica and thoroughly cleaned glass substrates at room temperature. Films deposited at room temperature have resistance typically in MW range. Structural studies were carried out with X-ray diffraction measurements on Cu_2SeTe films deposited at room temperature. In situ electrical conductivity was carried out on the films deposited at room temperature with the aim to study the effect of thickness of films on electrical conductivity. The conductivity and activation energy at 353K were estimated to be of the order of 10~(-6) mho/cm and 1.0 to 0.4eV, respectively. The results have shown that the electrical conductivity increases with the increase of film thickness. The activation energy was estimated from the lnσ v/s 1/T plots. The results were discussed with the existing models available in the literature. Cu_2SeTe is a highly useful material for solar temperature controllers and opto-electronic applications. The average particle size was 3 nm on glass deposited films and 9 nm on films deposited on mica substrate. Thermoelectric power of Cu_2SeTe films increase with increase of temperature and thickness.