X-ray absorption spectroscopy study of Ga-doping in reactively sputtered ZnO films

•Ga doped ZnO films grown by reactive cosputtering of GaAs and Zn in Ar-O2 mixture.•Resistivity increases from 10−3 Ω-cm to 0.2 Ω-cm as O2 in mixture changed from 5 to 6%.%•X-ray absorption studies reveal the nature of Ga incorporation in the films.•Ga is substitutionally incorporated in low resistivity Ga doped ZnO films.•Compensating GaZn+Oi complexes are formed in high resistivity Ga doped ZnO films.