Detector

Photodetector

Materials science

Responsivity

Semiconductor

Band gap

Avalanche photodiode

APDS

Physics

Optics

Dark current

Heterojunction

Optoelectronics

ACS Nano

Solar blind photodetectors with a cutoff wavelength within the 200-280 nm region is attracting much attention due to their potential civilian and military applications. The avalanche photodetectors (APDs) formed based on wide-bandgap semiconductor Ga2O3 are expected to meet emerging technological demands. These devices, however, suffer from limitations associated with the quality of as-grown Ga2O3 or the difficulty in alleviating the defects and dislocations. Herein, high-performance APDs incorporating amorphous Ga2O3 (a-Ga2O3)/ITO heterojunction as the central element have been reliably fabricated at room temperature. The a-Ga2O3-based APDs exhibits an ultrahigh responsivity of 5.9 × 104 A/W, specific detectivity of 1.8 × 1014 Jones, and an external quantum efficiency up to 2.9 × 107% under 254 nm light irradiation at 40 V reverse bias. Notably, the gain could reach 6.8 × 104, indicating the outstanding capability for ultraweak signals detection. The comprehensive superior capabilities of the a-Ga2O3-based APDs can be ascribed to the intrinsic carrier transport manners in a-Ga2O3 as well as the modified band alignment at the heterojunctions. The trade-off between low processing temperature and superior characteristics of a-Ga2O3 promises greater design freedom for realization of wide applications of emerging semiconductor Ga2O3 with even better performance since relieving the burden on the integration progress.

Ultrahigh Gain Solar Blind Avalanche Photodetector Using an Amorphous Ga<sub>2</sub>O<sub>3</sub>-Based Heterojunction

Ultrahigh Gain Solar Blind Avalanche Photodetector Using an Amorphous Ga2O3-Based Heterojunction

Ultrahigh Gain Solar Blind Avalanche Photodetector Using an Amorphous Ga₂O₃-Based Heterojunction