Effect of air and nitrogen annealing on TiO₂/Cu₂O heterojunction photoelectrochemical solar cells

TiO₂/Cu₂O heterojunction solar cells have been successfully synthesized by an electrochemical route. The structural, morphological and optical properties of TiO₂/Cu₂O heterojunction solar cells were studied using x-ray diffraction, scanning electron microscopy and UV–vis spectroscopic techniques. The change in morphology is observed due to the effect of the annealing atmosphere on TiO₂/Cu₂O heterojunction. The surface morphological study shows truncated triangular and nanostar-like Cu₂O material using air and nitrogen annealing. The oxidation state of TiO₂ and Cu₂O materials was studied by x-ray photoelectron spectroscopy. The J – V characteristics curve shows maximum 0.31% photoconversion efficiency of nitrogen-annealed TiO₂/Cu₂O heterojunction solar cells. (paper)