Ga₂O₃/GaN Heterostructural Ultraviolet Photodetectors with Exciton-Dominated Ultranarrow Response

Abstract

Ultraviolet photodetectors have demonstrated a wide range of applications, e.g., missile launching, tracking detection, environmental monitoring, etc. This Article presents an ultraviolet photodetector based on a Ga2O3/GaN heterostructure that is equipped with tunable multiband detectivity via bias voltage and a record ultranarrow response. Particularly, this spectral response can be tuned from ultraviolet-C to ultraviolet-A by modulating the depletion region of the photodetector via adjusting bias. Under a higher bias, a photoresponse with a full-width at half-maximum of ∼4 nm at 363 nm is achieved. This ultranarrow response reaches 2.58 × 103 A/W and an external quantum efficiency of (8.84 × 105)% under 28 V bias. The photoluminescence, photoluminescence excitation, and light-absorption measurements suggest that this ultranarrow-band detectivity can be ascribed to the field-enhanced exciton ionization process in the GaN layer. The high responsivity can be attributed to the internal gain of the photodetector originating from the relatively large valence band offset between the Ga2O3 and GaN layers. This work provides a promising approach to the development of high-performance and versatile multiband ultraviolet photodetectors with electrical tunability. It is also worth highlighting that the features of inexpensive manufacturing and easy scalability are particularly attractive for mass production.

Ga2O3/GaN Heterointerface-Based Self-Driven Broad-Band Ultraviolet Photodetectors with High Responsivity

“…Further, Kalra et al fabricated a β- Ga 2 O 3 /GaN vertical MSM UVPDs with a responsivity of 3.7 A/W at 256 nm under a 5 V applied bias. Later, Tang et al fabricated a GaN/Ga 2 O 3 heterostructure, which exhibited a responsivity of 1 A/W at a 4 V applied bias under 254 nm light illumination.…”

Lattice-aligned gallium oxynitride nanolayer for GaN surface enhancement and function extension

“…Apart from the desired band alignment with GaN, the large bandgap of GaON also brings potential benefits, such as stronger electric-field strength and hot-carrier immunity. Therefore, the responsivity of GaN photodetectors can be greatly improved through a field-enhanced exciton ionization process triggered by a high electrical field [53,54]. By applying the GaON nanolayer, the device breakdown voltage can be boosted to a higher value [31], allowing enough operating room for a high electrical field that enables the field-enhanced exciton ionization process.…”

Anisotropic dependence of radiation from excitons in Ga2O3/MoS2heterostructure

“…E.g. high breakdown electric eld in b-Ga 2 O 3 /graphene vertical barrister heterostructure., 24 Ga 2 O 3 /GaN heterostructural ultraviolet photodetectors, 25 deep-ultraviolet photodetection using single-crystalline b-Ga 2 O 3 /NiO heterojunctions, 26 ultrahigh deep-UV sensitivity in graphene-gated b-Ga 2 O 3 phototransistors, 3 and PdCoO 2 /b-Ga 2 O 3 Schottky diodes for hightemperature operation. 12 Another emerging 2D semiconductors with a sizable direct bandgap and novel physical properties are monolayer group VI transition metal dichalcogenides (TMDs).…”