P-type β-Ga2O3 films were prepared by Zn-doping using RF magnetron sputtering

Abstract

The XRD patterns show that the peak position of the Zn-doped β-Ga 2 O 3 films shifts to lower angles with the substrate temperature decreasing from 700℃ to room temperature, indicating the incorporation of Zn into Ga 2 O 3 films. Because the ion radius of Ga 3+ is 0.61Å and Zn 2+ is 0.74Å, the lattice spacing expanses with the increase of Zn concentration and thus the diffraction angle of the characteristic peak becomes smaller. The photoelectric response measurements show that the Zn-doped β-Ga 2 O 3 film based photodetectors manifest much lower dark-current and higher photo-to-dark current ratio. • P-type Ga 2 O 3 films were obtained by Zn doping using radio frequency magnetron sputtering method. • The doping concentration of Zn has a close relationship with temperature. • Zn-doped β-Ga 2 O 3 based photodetector manifested much lower dark-current and higher photo-to-dark current ratio. Zn-doped Ga 2 O 3 films were prepared using RF magnetron sputtering method at various deposition temperatures. Hall measurement demonstrated the present Zn-doped β-Ga 2 O 3 film was p -type conductivity. The XRD and XRF measurements showed the Zn dopant concentration increased with the decrease of temperature so that the position of the characteristic peak shifted to lower angles. The UV absorption spectra showed that the bandgaps became narrower with the doping concentration of Zn atom increasing. The pure and Zn-doped β-Ga 2 O 3 films were used to fabricate the photodetectors with MSM structure, respectively. The photoelectric response measurements showed that the Zn-doped specimen manifested much lower dark-current and higher photo-to-dark current ratio, but slower photoresponse speed.