A report on the preparation of p-type ZnO thin films, codoped with Al and N, on n-type Si (100) substrate by RF sputtering technique is presented. The as-grown films were found to be n-type and the conduction was converted to p-type on annealing in Ar ambient. ZnO homojunction was fabricated by growing a three-dimensional ZnO hybrid structure of p-type ZnO films, n-type ZnO nanowire and n-type Al-doped ZnO films in order. The current-voltage characteristics clearly showed a diode like rectifying behavior. Room temperature photoluminescence spectra showed dominant peak at 3.20 eV with a broad deep level emission. The electroluminescence spectrum of heterojunction structure exhibited deep level emission at 2.37 eV and ultraviolet emission at 3.20 eV when the injected current attained 100 mA. Published by Elsevier B.V.