Dual-band and dual-mode ultraviolet photodetection characterizations of Ga2O3/Al0.1Ga0.9N homo-type heterojunction

The deep-ultraviolet (DUV) photodetectors (PDs) have important applications in lots of fields. Thus,developing self-powered DUV PDs and excavating the inherent mechanism seem seriously crucial to achievingfurther actual applications. The construction of heterojunction can lead to many desired characteristics inoptoelectronic devices. In the field of DUV photodetection, Ga2O3 has been a popular subject for constructingDUV PDs. So, it is necessary to develop self-powered Ga2O3-based DUV PDs through fabricating itsheterogeneous structure. Therefore, in this work, the Ga2O3/Al0.1Ga0.9N heterojunction DUV PD is fabricatedand discussed, which can achieve 254 and 365 nm DUV light photodetection. At positive voltages and negativevoltages, the heterojunction PD can operate in a photoconductive mode or a depletion mode, respectively. Inview of the PD performance, it displays decent dark current and DUV photoresponses. At voltage of 5 and -5 V,under 254 nm DUV light illumination, the photoresponsivity (R) is 2.09 and 66.32 mA/W, respectively, whileunder 365 nm DUV light illumination, R is 0.22 and 34.75 mA/W, respectively. In addition, under the built-inelectric field (Ebuilt-in), R is 0.13 and 0.01 mA/W for 254 nm and 365 nm DUV light illumination, respectively.In all, the fabricated heterojunction PD displays promising prospects in the coming next-generationsemiconductor photodetection technology. The results in this work indicate the potential of Ga2O3/Al0.1Ga0.9N heterojunction with high performance DUV photodetection. Furthermore, except for the characterizations of thematerials and photodetector, in the end of this paper, the operating mechanism of the dual-band dual-modeheterojunction PD is analyzed through its heterogeneous energy-band diagram. It is concluded that theillustrated dual-band dual-mode Ga2O3/Al0.1Ga0.9N heterojunction can be sensitive to UVA waveband and UVCwaveband in the electromagnetic spectrum, extending its photodetection region. And, the dual-mode(photoconductive mode and depletion mode) photodetection indicates two kinds of carrier transports in one PD,which can be attributed to the successful construction of the N-N tomo-type Ga2O3/Al0.1Ga0.9N heterojunction

Automated summary

In this study, a Ga2O3/Al0.1Ga0.9N heterojunction DU PD was successfully fabricated and its photodetection performance was evaluated. The experimental results showed that the PD exhibited good photocurrent response under 254nm and 365nm DUP light illumination, and had low dark current. In addition, the operating mechanism of the dual-band dual-mode heterojunction PD was analyzed, and it was found that it could be sensitive to UVA and UVC wavelengths, expanding its photodetection range.