Morphology-property relationships of CdZnTe films prepared via radio frequency magnetron sputtering

The polycrystalline CdZnTe films are promising material for fabrication of X-ray detection and solar cells. In this study, a pebble-like grain, hexagonal grain and worm-like grain of CdZnTe films were prepared via radio frequency magnetron sputtering. The morphology and properties of CdZnTe films were then characterized using atomic force microscopy, 2-D grazing-incidence wide-angle X-ray scattering, Raman spectra, transmission spectra and current–voltage curves. Accordingly, the CdZnTe crystal cell was found to be haphazardly arranged in the pebble-like grain, consequently demonstrating less anisotropy. In addition, the pebble-like grain film possessed a higher resistivity in light of the reduced anisotropy. In regard to the worm-like grain and hexagonal grain films, most CdZnTe (111) crystal planes were noted to be parallel to the sample surface. The worm-like grain film had the lowest absorption coefficient within the visible light range. Furthermore, the hexagonal grain film was shown to have the largest particle size, best crystallinity and lowest resistivity. The conductive mechanism of CdZnTe films of different morphologies was also discussed.