Ga₂O₃ Schottky Avalanche Solar‐Blind Photodiode with High Responsivity and Photo‐to‐Dark Current Ratio

Abstract

Solar‐blind photodetectors have attracted extensive attention due to their advantages such as ultra‐low background noise and all‐weather. In this study, the planar Ti/Ga2O3/Au Schottky avalanche photodetector (APD) is fabricated based on β‐Ga2O3 epitaxial film on the sapphire substrate grown by metal–organic chemical vapor deposition. The Schottky APD exhibits a high responsivity of 9780.23 A W−1, an ultrahigh photo‐to‐dark current ratio of 1.88 × 107, an external quantum efficiency of 4.77 × 106%, a specific detectivity of 9.48 × 1014 Jones, with an ultrahigh gain of 1 × 106 under 254 nm light illumination at 60 V reverse bias, indicating high application potential for solar‐blind imaging. The superior photoresponse performances ascribe to the effective carrier avalanche multiplication, which contributes to the high photocurrent, and the high quality Schottky junction depletion, which leads to the low dark current.

High-Performance ε-Ga2O3 Solar-Blind Photodetectors Grown by MOCVD with Post-Thermal Annealing

“…Solar-blind photodetectors (SBPDs) have garnered considerable attention for their applications in missile warning, optical communication, environmental monitoring, flame detection, and various other fields [1][2][3]. Recently, solar-blind UV photodetectors based on ultrawide bandgap semiconductors like AlGaN, MgZnO, and Ga 2 O 3 have gained significant prominence [4][5][6]. Among these materials, Ga 2 O 3 stands out as a promising candidate for SBPDs due to its ultra-wide and direct bandgap (4.5-5.2 eV), which is suitable for the solar-blind region without the need for bandgap modulation through alloying processes [7].…”