Electroless Deposition of p-type Cuprous Oxide Thin Film for Solar Application

Abstract

Solar cells hold a promising prospect in the foreseeable future. Presently cuprous oxides (Cu2O), due to their excellent photovoltaic properties, are being considered as p-type semiconductor materials for solar cell. This work aims at electroless deposition of p-type Cu2O thin film on copper substrate and studying its various properties through characterizations. A bath containing varying amounts of CuCl2.2H20, CoCl2.6H20, NaH2PO2.6H20 and KNaTar.4H2O (Potassium sodium tartrate tetrahydrate) was used for the process. NaOH pellets were used in order to get the desired pH level ranging from 11 to 14. The bath temperature was varied between 30°C to 70°C. The deposited films were characterized by Scanning Electron Microscope (SEM) equipped with Energy Dispersive Spectroscopy (EDS), X-ray diffractometer (XRD) and UV spectroscopy. It was observed that thin films were deposited at different conditions and uniform deposition of Cu2O thin film was visible at pH 14. The coating thickness was found to be in the range of 0.48 to 4.6 μm. The bandgap for the deposited Cu2O was found to be in the range of 1.3-1.4 eV. Some variation in results at different pH were observed and the reasons were identified.