Studies on SILAR deposited Cu₂O and ZnO films for solar cell applications

SILAR deposited ZnO/Cu₂O/ITO heterostructures were prepared and their photoresponse property was studied for various thickness of Cu₂O layer. The ZnO thin films were grown using a solution comprising of high purity zinc sulphate, and sodium hydroxide, and the Cu₂O films were deposited using an aqueous bath containing copper sulphate pentahydrate, sodium thiosulfate and sodium hydroxide, respectively. X-ray diffractometer analysis of the films have shown highly oriented growth of Cu₂O and ZnO films along (111) and (002) planes, respectively. Scanning electron microscope study has shown the nanorod morphology of both Cu₂O and ZnO films, the Cu₂O film has shown increased thickness and grain size with the increasing dipping cycles. Optical absorption measurements of the films have shown increase of absorbance with the increase of thickness of Cu₂O films, and the ZnO film has shown a maximum of 80 % transmittance. The solar cell efficiency of Cu₂O/ZnO structure was measured and it has been found to increase with the increase of the Cu₂O film thickness.