p-Type dye-sensitized solar cell based on nickel oxide photocathode with or without Li doping

•Microwave-assisted hydrothermal synthesis of NiO nanostructures with Li-doping at low temperature.•p-Type dye-sensitized solar cell based on NiO photocathode.•Study on the effect of Li doping concentration on the cell performance. Nickel oxide (NiO) nanostructures are synthesized using a microwave-assisted hydrothermal method. The hydrothermal bath has a solution of nickel salt mixed with precipitating agent. During the synthesis the microwave temperature, the concentration of nickel salt and precipitating agent along with the pH of the reaction solutions are changed and different morphologies of nickel oxide are obtained. The resulting nickel oxide nanostructures are characterized using X-ray diffraction, scanning electron microscopy, transmission electron microscopy, Brunauer–Emmett–Teller method and X-ray photoelectron spectroscopy. Thus formed NiO has been used as a photocathode in dye-sensitized solar cell. Lithium doped NiO showed better IPCE as well as solar to electrical conversion efficiency than the undoped NiO.