Transport Mechanism of Enhanced Performance in an Amorphous/Monoclinic Mixed-Phase Ga₂O₃ Solar-Blind Deep Ultraviolet Photodetector

Abstract

Recently, as an emerging material, ultrawide bandgap Ga2O3 has been investigated extensively in solar-blind deep-ultraviolet (DUV) photodetectors (PDs). High sensitivity and signal-to-noise ratio of PDs are essential for the detection of solar-blind DUV signals; however, such factors are often not mutually compatible. In the present study, an amorphous/monoclinic homogeneous mixed-phase structure was demonstrated to be significantly beneficial in enhancing the comprehensive performance of Ga2O3 solar-blind DUV PDs, especially with respect to sensitivity and the signal-to-noise ratio. Further experimental and theoretical findings provide insights on the transport mechanism of enhanced performance in the mixed-phase Ga2O3 solar-blind DUV PD. For effectively separating the photogenerated carriers, a type-II band alignment between amorphous and crystalline Ga2O3 can be exploited. Furthermore, the change of the barrier height of the mixed-phase interface also has a significant impact on the transport properties of the mixed-phase Ga2O3 PD. Additionally, the potential applications of mixed-phase Ga2O3 PD in high-voltage corona discharge were explored, and clear and stable corona discharge signals were obtained. The results of the present study may promote understanding of DUV photoelectronic devices with various mixed-phase Ga2O3 materials and provide an efficient approach for promoting comprehensive performance in future solar-blind detection applications.

Keywords

• Ga₂O₃
• mixed-phase structure
• solar-blind photodetector
• transport mechanism
• DFT calculation