X-ray diffraction and Raman scattering studies in 10B+-implanted Cd0.96Zn0.04Te thin films prepared by vacuum evaporation

Abstract

Polycrystalline Cd0.96Zn0.04Te thin films prepared by vacuum evaporation onto thoroughly cleaned glass substrates kept at room temperature were implanted with mass-analyzed beams of 100 keV boron ions (10B+) at various doses ranging from 1012 to 1014 ions cm−2. The X-ray diffraction pattern of the as-deposited film shows zinc blende structure with a predominant orientation along the 〈1 1 1〉 plane. The implanted films show a decrease in the 〈1 1 1〉 peak intensity and increase in the full-width at half-maximum (FWHM) with implantation dose. The surface roughness (rms) of the as-deposited film evaluated by atomic force microscopy is 3.7 nm and the value of roughness is found to increase with implantation dose. Raman spectra of the as-deposited films show longitudinal optic (LO) and transverse optic (TO) modes, which arise from CdTe-and ZnTe-like vibrations. There is no significant change in the Raman peak position due to implantation but the FWHM is found to be increased. This is probably due to the implantation-induced lattice disorder. The relative intensity of the Raman peaks and the area under the peaks were found to increase with implantation dose. These results are explained on the basis of the implantation-induced surface roughness and lattice disorder.