Transparent conductive hydrogenated Mg and Ga co-doped ZnO (HMGZO) thin films for solar cells were deposited via pulsed direct current (DC) magnetron sputtering on glass substrates at a substrate temperature of 553 K. The structural, morphological, electrical, and optical properties of HMGZO thin films were investigated with various H-2 flow rates. The experiment results showed that the HMGZO thin films are polycrystalline with a hexagonal wurtzite structure exhibiting a preferred (002) crystal plane orientation and typical HMGZO thin films present cone-like texture surface. The carrier concentration rapidly increases from 7.57 x 10(19) cm(-3) to 5.25 x 1020 cm-3 with increasing the H-2 flow rate from 0 sccm to 4.0 sccm. Optical measurements indicated that the optical band-gap (E-g) of HMGZO thin films varies from 3.43 eV to 3.66 eV with adjusting H-2 flow rate from 0 sccm to 4.0 sccm. The glass/HMGZO thin film deposited at the H-2 flow rate of 4.0 sccm exhibits the lowest resistivity of 6.24 x 10(-4) Omega cm (sheet resistance Rs similar to 8.68 Omega) and an average transmittance (Ta) of 78.8% in the wavelength range from 340 nm to 1100 nm. Burstein-Moss band-filling, band gap renormalization effects determined by carrier concentrations and the incorporation of Mg atoms together contribute to an E-g widening phenomenon. The electron mobility of HMGZO thin films can be effectively improved through thermal annealing process. Finally, the HMGZO thin film was preliminarily applied in pin a-Si:H thin film solar cell with an efficiency of 8.20% (V-oc=0.904 V, J(sc)=12.906 mA/cm(2) and FF=0.702). (C) 2014 Elsevier B.V. All rights reserved.