The study of electro-deposited CuSCN thin films and optimize electrolyte: Material analyses, mechanism investigation

Abstract

When optimizing the electrolyte ion ratio and depositing an excellent characteristic CuSCN thin film would offer a significant promising opportunity for CuSCN which will be widely used in optoelectronic device. In this kind of work, CuSCN films are eventually prepared using electrodeposition method and how electrolyte ion ratio influences the morphology and electrical properties of CuSCN thin films and the corresponding mechanisms are studied in detail. The thin films which are deposited with electrolyte ion ratio Cu: SCN 1:2 (named as CuSCN (1:2)) generally exhibited more excellent mobility which in-fact solve the CuSCN biggest challenge: low conductivity compared to other P-type materials which makes it low mobility. The mobility of non-stochiometric CuSCN films with ESCN/Cu ratio of 2 is gradually increased by 228 times as compared with that of stochiometric films. The phenomenon can be usually ascribed to the Cu vacancy in CuSCN (1:2) which is entirely influenced by the microstructure of CuSCN films. The valance band of CuSCN (1:2) is 4.77 near ITO work function (4.8 eV). It can as well reduce the energy barrier between ITO and CuSCN which can increase the efficiency of the device such as photodetector and solar-cell which use ITO and CuSCN as the electrode and P-type material. Up to the core knowledge of the author, it is the first report about the properties of non-stochiometric α-CuSCN films.