Micro-sized ZnO rods on SnO2 coated glass substrate were obtained by spray pyrolysis method. Then a p-type nanorod ZnO layer was deposited on this micro-sized n-ZnO to produce a p-n homojunction. Temperature dependent current-voltage (I-V) characteristics were measured in the temperature range 150-300K with a step of 25 K. The current-voltage characteristics exhibit electrical rectification behavior. The zero bias barrier height Phi(b0) increases and ideality factor n decreases with an increase in temperature. The apparent Richardson constant and mean barrier height were found to be 0.062 A cm(-2) K-2 and 0.122 eV, respectively in the range 150-300K. After barrier height inhomogeneities correction, the Richardson constant and the mean barrier height were obtained as 179.05 A cm(-2) K-2 and 0.884 eV respectively. (C) 2010 Elsevier B.V. All rights reserved.