Sustainable hydrogen production through photoelectrochemical water splitting using metal oxide is a promising approach for the chemical storage of solar energy, but for most of the metal oxide the bandgap must be reduced to shift the absorption into the visible regions to use sunlight more efficiently. A detailed investigation of Al and N co-doped ZnO thin films are presented. Al and N co-doped ZnO thin films, ZnO:(Al,N), are synthesized by radio-frequency magnetron sputtering. The ZnO:(Al,N) films showed enhanced N incorporation and crystallinity as compared to ZnO:N thin films deposited in the same gas ambient. As a result, ZnO:(Al,N) films deposited showed higher photocurrents due to N incorporation and crystallinity.