Electrical characterization of ZnO/NiO p-n junction prepared by the sol-gel method A. Merih Akyuzlu, Fethi Dagdelen, Ahmet Gultek, A. A. Hendi and Fahrettin Yakuphanoglu Eur. Phys. J. Plus, 132 4 (2017) 178 Published online: 21 April 2017 DOI: 10.1140/epjp/i2017-11442-8