N-In codoped ZnO thin films were prepared by ion beam enhanced deposition method (IBED) and were annealed in nitrogen and oxygen ambient after deposition. The influence of post-annealing on structure, electrical and optical properties of thin films were investigated. As deposited and all post-annealed samples showed preferential orientation along (0 0 2) plane. Electrical property studies indicated that the as deposited ZnO film showed p-type with a sheet resistance of 67.5 k Omega. For ZnO films annealed in nitrogen with the annealing temperature increasing from 400 to 800 degrees C, the conduction type of the ZnO film changed from p-type to n-type. However, for samples annealed in oxygen the resistance increased sharply even at a low annealing temperature of 400 degrees C and the conduction type did not change. Room temperature PL spectra of samples annealed in N-2 and in O-2 showed UV peak located at 381 and 356 nm, respectively. (c) 2006 Elsevier B.V. All rights reserved.