Wide bandgap inorganic metal oxide heterojunctions p-NiO/n-ZnO have been prepared by two low temperature solution growth techniques. Namely, one-dimensional ZnO nanostructure arrays electrodeposited in a pulsed mode, and nanocrystalline NiO films synthesized via Successive Ionic Layer Adsorption and Reaction (SILAR). The crystal structure, morphology, and optical properties of NiO films and NiO/ZnO heterostructures were investigated both before and after annealing in air. The analysis of the dark current vs. voltage characteristics and temporal response curves of the NiO films and corresponding NiO/ZnO heterostructures have shown the promise of their use in the effective UV-photodetectors. Poor photovoltaic characteristics of the test samples on the base of obtained NiO/ZnO heterostructures probably associated with their not quite optimal design, and with too large series resistances and diode ideality factors of the manufactured p-NiO/n-ZnO heterojunctions, that will be corrected by scrutinizing the defects in the metal oxides and through the improvement of the NiO/ZnO heterostructure design. Solving these problems will provide the effective application of the wide bandgap metal oxide NiO/ZnO heterostructures prepared by low temperature solution growth in the UV-active semi-transparent solar cells.