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

• Main Authors: Haowen Liu, Honglin Li, Shuren Zhou, Hong Zhang, Shiqiang Fan, Yuting Cui, Chunyang Kong, Lijuan Ye, Yuanqiang Xiong, Wanjun Li
• Format: Article
• Language: English
• Published: MDPI AG 2021-09-01
• Series: Crystals
• Subjects: Ga₂O₃; mixed-phase structure; solar-blind photodetector; transport mechanism; DFT calculation
• Online Access: https://www.mdpi.com/2073-4352/11/9/1111

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.