Solar to electric and–chemical energy conversion applications with the indigenously developed nickel oxide coatings

Abstract

The overall objective of this research was to deposit metal oxide semiconductor in order to convert solar energy into electric and chemical energies. Nickel oxide (NiO) was chosen as the required metal oxide semiconductor for these applications due to its p-type nature, stability and wide band gap. The main focus of this research was to use a unique sintering technique assisted through microwave plasma for the fabrication of NiO electrodes. The performance of microwave plasma sintering also known as rapid discharge sintering (RDS) was compared with conventional furnace treatments. For solar to electric energy conversion, suitable dye is used to sensitize both RDS and furnace sintered NiO coatings to prepare p-type dye-sensitized solar cells (DSSCs). A tenfold increase in the photovoltaic performance was observed for the RDS treated NiO coatings due to more open structure, superior adhesion to the substrate, smaller grain size and increased level of dye adsorption as compared to furnace sintered NiO coatings. A preliminary sensitization study of these NiO coatings with Ruthenium-Rhenium complex dye demonstrated the ability of these metal oxides to adsorb this dye with no change in chemical structure for the potential application of NiO coatings in the reduction of CO2.