Copper (I) Chloride is a wide band gap semiconductor with great potential for silicon-based optoelectronics due to the fact that is closely lattice matched with silicon. This work examines the deposition of CuCl thin films by magnetron sputtering on silicon and glass substrates. Film structural and morphological properties are studied with X-ray diffraction and atomic force microscopy. Optical absorbance and luminescence spectra of CuCl thin films are analysed in order to study the excitonic features. The influence of deposition process parameters and post annealing on the film properties are also reported.
γ-CuCl is a wide-bandgap (Eg = 3.395eV), direct bandgap, semiconductor material with a cubic zincblende lattice structure. Its lattice constant, aCuCl = 0.541 nm, means that the lattice mismatch to Si (aSi = 0.543 nm) is <0.5%. γ-CuCl on Si-the growth of a wide-bandgap, direct bandgap, optoelectronics material on silicon substrates is a novel material system, with compatibility to current Si based electronic/optoelectronics technologies. The authors report on early investigations consisting of the growth of polycrystalline, CuCl thin films on Si (100), Si (111), and quartz substrates by physical vapour deposition. X-ray diffraction (XRD) studies indicate that CuCl grows preferentially in the <111> direction. Photoluminescence (PL) and Cathodoluminescence (CL) reveal a strong room temperature Z3 excitonic emission at ~387nm. A demonstration electroluminescent device (ELD) structure based on the deposition of CuCl on Si was developed. Preliminary electroluminescence measurements confirm UV light emission at wavelengths of ~380nm and ~387nm, due to excitonic behaviour. A further emission occurs in the bandgap region at ~360nm.