A p-type transparent oxide semiconductor, CuGaO2, was grown epitaxially on (111) single-crystalline yttria-stabilized zirconia (YSZ) substrates by pulsed laser deposition (PLD). Single-phase epitaxial films were obtained in narrow conditions: i.e. 725 <= T-s <= 780 degrees C at PO2 = 6 Pa, and 3 Pa <= PO2 <= 6 Pa at T-s =750 degrees C. The electrical conductivity of the as-deposited films was controlled from 3.3x 10(-5) S.cm(-1) to 1.7 x 10(-2) S center dot cm(-1) by increasing the oxygen partial pressure from 3 to 6.5 Pa. The hole concentration and Hall mobility of the most conductive film were 5x10(17) cm(-3) and 0.2 cm(2).V-1-s(-1), respectively. Estimated from the conductivity, the hole concentration was controlled from similar to 10(14) cm(-3) to similar to 10(17) cm(-3) by the oxygen partial pressure. Post-annealing at 1215 degrees C smoothed the films surface to 0.56 nm in the root-mean-squares roughness and increased the Hall mobility to 0.8 cm(2) V-1 center dot s(-1), which is the largest value among CuGaO2 films reported to date. (C) 2007 Elsevier B.V. All rights reserved.