Structural, morphological, optical and electrical properties of e-beam deposited nanocrystalline CdTe:Cu alloy thin films from mechanical alloyed samples

摘要

Cadmium telluride (CdTe) and copper incorporated CdTe (CdTe:Cu) alloys were prepared by mechanical alloying using a planetary ball mill. X-ray diffraction results showed that the prepared CdTe:Cu alloys belong to CdTe cubic system. Surface morphology of CdTe and CdTe:Cu alloys, investigated by scanning electron microscope shows the formation of agglomerated structures of various shapes. The prepared respective sample was used as the source material to deposit CdTe and CdTe:Cu alloy thin films by e-beam evaporation method. X-ray diffraction studies showed that the films grow along (111) plane. The crystallite size of the films varies in the similar to 28 to 37 nm range whereas the optical band gap is increased from 1.45 to 1.54eV with increasing copper concentration in the CdTe:Cu alloy films. The wavelength at which maximum optical transmittance occurred in CdTe is shifted from 900 nm to 837 nm due to various level of Cu concentration in CdTe:Cu alloy films. Intensity of the photoluminescence and Raman spectra of CdTe films is decreased due to increase in the Cu concentration in CdTe:Cu alloy film. Hall measurement studies revealed that 2wt.% and 4wt.% Cu concentration in CdTe:Cu alloy film gives a minimum resistivity of similar to 1.8 x 10(4) Omega cm. (C) 2017 Elsevier B.V. All rights reserved.