Influence of short-pulsed Ion irradiation on optical and photoelectrical properties of thin gallium oxide films

Abstract

In this work the influence of a short-pulsed ion irradiation with a high flux (∼5.5∙1019 cm−2s−1) on structure, optical and photo-electrical properties of gallium oxide thin films have been investigated. The films were produced by the radio-frequency magnetron sputtering method. A part of deposited films was annealed in the air environment (900 °C, 2 h) for synthesis of β-Ga2O3 phase. Obtained films were subjected to the short-pulsed ion irradiation (ion energy - up to 200 keV, pulse duration - 90 ns, current density on the target - up to 15 A/cm2). The influence of the annealing and the irradiation on spectral dependences of absorption, the bandgap width and the Urbach energy have been determined. It was found that irradiation leads to amorphization of crystalline β-Ga2O3 films and a significant change in optical characteristics. In addition, we measured the magnitude of surface dark and photoconductivity of the films. Also, the field and spectral dependences of the photosensitivity of the films were researched. As a result, it was established that short-pulsed irradiation improves the photoelectric properties of amorphous gallium oxide films. The reasons of it are discussed.

Keywords

• Gallium oxide
• Thin films
• Radiation resistance
• Magnetron sputtering
• Short-pulsed ion irradiation
• Radiation defects