Morphological, optical and electrical properties of γ CuCl deposited by vacuum evaporation

Abstract

In this study, we have investigated the microstructural and optical properties of thin films of CuCl grown by vacuum evaporation on amorphous silica glass, polycrystalline indium tin oxide (ITO) and Silicon (100) substrates. Room temperature X-ray diffraction measurements reveal that CuCl grows preferentially with a (111) orientation irrespective of the substrate. Atomic force microscopy measurements showed similar surface topologies and roughness for CuCl/Si, CuCl/ITO and CuCl/Glass structures. Photoluminescence measurements at 20 K revealed the bound bi-exciton N1, impurity bound exciton I1 and the free exciton Z3 occurring at 3.152 ± 0.002 eV, 3.18 eV, and 3.204 eV, respectively, for all three structures. In addition to this, temperature dependent impedance measurements using irreversible electrodes (Au) showed that the deposited CuCl is a mixed ionic and electronic semiconductor with a predominantly extrinsic cationic conduction mechanism at temperatures above ∼280 K and with electronic conduction dominant at temperatures below ∼265 K.