Under-Seawater Immersion β-Ga₂O₃ Solar-Blind Ultraviolet Imaging Photodetector with High Photo-to-Dark Current Ratio and Fast Response

Abstract

This work displays a photovoltaic solar-blind UV photodetector based on a β-Ga 2 O 3 photoelectrode/simulated seawater (NaCl). The photodetector exhibits extremely high photocurrent (6.70 μA); the responsivity can reach 23.47 mA W −1 , and the fastest response rise time is 40 ms under 213 nm illumination at zero bias, the responsivity is 25.10 mA W −1 at 0.8 V, and the photo-to-dark current ratio reaches a maximum of 4663, whose responsivity can be effectively adjusted by changing electrolyte concentration, ensuring a good working stability of this device. In addition, with original seawater as the electrolyte, the detector still achieves a high switching ratio (754) and stable detection under zero bias, demonstrating its capability for practical uses. What's more, we present the capability of the photodetector in seawater imaging. This work provides a method for solar-blind UV detection in seawater, which compensates for the limited detection of most current seawater detectors in the visible band, and can provide certain guidance in the field of seawater detection.

High-Performance Solar-Blind Photodetector Based on (010)-Plane β-Ga2O3 Thermally Oxidized from Nonpolar (110)-Plane GaN

“…Ga 2 O 3 is expected to have superior material properties compared to silicon carbide (SiC) and gallium nitride (GaN) in the applications of an electronic device because of its high breakdown electric field . As a result of the solar-blind photodetectors (SBPDs) fabricated on the basis of an UWBG semiconductor easily eliminating the interference from background noise sources, they are extensively applied to ultraviolet-related (sparkle, flame, explosion, and missile) early warning, ,, ozone hole monitoring, new generation short-distance space communication, biological and medical analysis, under-seawater detection, etc. Although AlGaN with a high Al content and MgZnO with a high Mg content are optional UWBG semiconductors to fabricate SBPDs, their application is severely limited.…”

A high-performance Ti3C2Tx/Lu2O3/GaN heterojunction deep ultraviolet photovoltaic photodetector enhanced via the dual-field coupling effect

“…6 Recently, wide-bandgap semiconductors represented by ternary alloy compounds (AlGaN, MgZnO, etc. ), 7–10 diamond, 11,12 Ga 2 O 3 , 13–15 etc. have been widely reported for use in the preparation of DUV PDs.…”

Hafnia-based oxide enhanced Ga2O3-based photodetectors via band engineering with ultralarge responsivity

“…1–4 For application as a DUV PD, multiple wide-bandgap semiconductors, like AlN, ZnO, GaN and Ga 2 O 3 , are of key relevance. 5–10 Ga 2 O 3 in particular offers an appropriate direct bandgap of ∼4.9 eV, high breakdown electrical field of ∼8 MV cm −1 , high absorption coefficient, and thermal stability among other advantageous properties, which make it an ideal DUV PD candidate. 11–16 Many research groups have been motivated to try to enhance the responsivity of the Ga 2 O 3 -based PDs, using a range of methods.…”