Impact of Al and Ga co-doping with different proportion in ZnO thin film by DC magnetron sputtering

Characteristic properties of ZnO are remarkably changed due to presence of small impurity or native defects. As such intentional doping of III group elements is the front runner for researchers. In the present paper, Al doped ZnO and Ga doped ZnO and Al–Ga co-doped ZnO (AGZO) thin films are deposited on the glass substrate by DC magnetron sputtering. The result of different proportion of co-doped materials is highlighted and is compared with the doped films. It is observed that the co-doped ZnO thin films showed better optical, structural and electrical properties as compared to doped ZnO thin films. In the case of co-doped samples resistivity in the order of 10⁻⁴ ohm-cm is obtained with higher carrier concentration and high optical transparency. X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR) studies were done to discuss the changes observed in the structural properties. AFM result suggests the better co-doped films with less defects for practical implication to the devices. More significantly for AGZO (1:1) thin film, better optical, electrical and structural properties are obtained with a low resistivity of 5.4 × 10⁻⁴ ohm-cm and transmittance more than 80 % in the visible range of light.