The ZnO films doped with 3 wt% phosphorus (P) were produced by activating phosphorus doped ZnO (ZnO:P) thin films in oxygen (O-2) ambient at 600 degrees C for 30, 60, 90 and 120 min, respectively. As-deposited films doped with phosphorus are highly conductive and n type. All the films showed p-type conduction after annealing, in an O-2 ambient atmosphere. The activation energies of the phosphorus dopant in the p-type ZnO under O-2 ambient gases indicate that phosphorus substitution on the O site yielded a deep level in the gap. With a further increase of the annealed durations, the crystalline quality of the ZnO:P sample is degraded. The best p-type ZnO:P film deposited at 600 degrees C for 30 min shows a resistivity of 1.85 Omega cm and a relatively high hole concentration of 5.1 x 10(17) cm(-3) at room temperature. The films exhibit a polycrystalline hexagonal wurtzite structure without preferred orientation. The mean grain sizes are calculated to be about 60, 72, 78, 85 and 90 nm for the p-type ZnO films prepared at 600 degrees C for 30, 60, 90 and 120 min, respectively. Room temperature photoluminescence (PL) spectra of the ZnO film exhibit two emission bands-paramount excitonic ultraviolet (UV) emission and weak deep level visible emission. The excellent emission from the film annealed at 600 degrees C for 30 min is attributed to the good crystalline quality of the p-type ZnO film and the low rate of formation of intrinsic defects at such short duration. The visible emission consists of two components in the green range. (C) Koninklijke Brill NV, Leiden, 2010