Effect of CuS buffer layer on the structural and optical properties of TeO 2 nanowires: a comparative study

Abstract The current work concerns with the effects of cupper sulfide (CuS) buffer layer on morphological, structural and optical properties of tellurium dioxide (TeO 2 ) nanostructured thin films synthesized by vapor transport method. Single crystalline tetragonal TeO 2 crystallographic phase with enhanced peak intensity and crystallinity for CuS/TeO 2 film are observed by x-ray diffraction analysis. Scanning electron microscopy examinations revealed small rod-like morphology for TeO 2 and randomly oriented nanowires morphology for CuS/TeO 2 samples. The estimated optical band gap energies were 3.78 and 3.63 eV for TeO 2 and CuS/TeO 2 nanostructured films, respectively. The photoluminescence of CuS/TeO 2 film was enhanced and red-shifted from 450 to 455 nm by the presence of CuS layer. The effective charge carrier life times were 0.14 ns and 1.92 ns for TeO 2 and CuS/TeO 2 films, respectively. These results could be beneficial for optoelectronic devices such as light emitting devices.