Economically viable copper oxide nano particles were prepared via a novel simplistic synthesis method using oleic acid as a solvent, surfactant and capping agent with varying reaction temperature (200 degrees C, 300 degrees C and 400 degrees C) by solvothermal technique to develop a high efficiency solar cell. The influence of calcined temperature on crystalline size, purity, morphology, structural phase transition and stoichiometric formation of copper oxide powders were investigated by using powder X-ray diffraction, Scanning Electron Microscopy and X-ray Photoelectron Spectroscopy (XPS). The band gaps were calculated by optical studies. The luminescence spectra exhibit band to band transition of copper oxide nano particles. From TGA profile the mass reduction was occurred below 300 degrees C. The growth mechanism of Copper oxide nano particles from copper chloride dihydrate with oleic acid (OA) investigated. The maximum overall conversion efficiency of 0.863% has been achieved from I to V characteristic study in favor of copper oxide nano particles calcined at 400 degrees C. (C) 2012 Elsevier B.V. All rights reserved.