Trivalent/bivalent metal ions doped TiO2 thin films (M,Ti1-xO2, M =Cr3+,Fe3+, Ni2+,Co2+, Mn2+ and x= 0.01, 0.05, 0.1, 0.15, 0.2) were deposited on Indium-tin oxide (ITO) coated glass substrates by spin coating technique. X-ray photoelectron spectroscopy (XPS) showed TO oxidation state of the Ti2p band in the doped p-TiO2. The homogenous MxTi(1-x)O(2) was used to support n-ZnO thin films with thickness similar to 40-80 nm and vertically aligned n-ZnO nanorods (NR) with length similar to 300 nm and 1.5 mu m. Current (I)-voltage (V) characteristics for the Ag/n-ZnO/MxTi1-xO2/ITO/glass assembly showed rectifying behavior with small turn-on voltages (V-0)< 1 V. The ideality factor (eta) and the resistances in both forward and reverse bias were calculated. The temperature dependence performance of these bipolar devices was performed and variation of the parameters with temperature was studied. (C) 2011 Elsevier B.V. All rights reserved.