Recent advances in Ga-based solar-blind photodetectors

Abstract

Solar-blind ultraviolet photodetectors have many advantages, such as low false alarm rates, the ability to detect weak signals, and high signal-to-noise ratios. Among the various functional solar-blind ultraviolet photodetectors, Ga-based alloys of AlGaN and Ga 2 O 3 are the most commonly adopted channel semiconductor materials and have attracted extensive research attention in the past decades. This review presents an overview of the recent progress in Ga-based solar-blind photodetectors. In case of AlGaN-based solar-blind ultraviolet photodetectors, the response properties can be improved by optimizing the AlN nucleation layer and designing the avalanche structure. On the other hand, we also discuss the morphology and growth methods of Ga 2 O 3 nanomaterials and their effect on the performance of the corresponding solarblind photodetectors. The mechanically exfoliated Ga 2 O 3 flakes show good potential for ultraviolet detection. Also, Ga 2 O 3 nanoflowers and nanowires reveal perfect response to ultraviolet light. Finally, the challenges and future development of Ga-based functional solar-blind ultraviolet photodetectors are summarized.

Unusual effects of nanowire-nanowire junctions on the persistent photoconductivity in SnO2 nanowire network devices

“…This phenomenon led to the development of highly sensitive photodetectors, i.e. devices that convert incoming photons into corresponding electrical signals [20][21][22][23][24][25]. When built from intrinsic semiconductors, the photoconductivity of these devices is a result of the excitation of electrons from the valence band (VB) to the conduction band (CB); when built from extrinsic semiconductors, the photoconductivity is also a result from the excitation of carriers from the impurity levels to the conduction or valence bands [26,27].…”

Ultraviolet photodetectors based on wide bandgap oxide semiconductor films

“…Solar-blind UV photodetectors can accurately response to a very weak signal even under sun or room illumination. Monoclinic Ga 2 O 3 (β -Ga 2 O 3 ), with an intrinsic bandgap E g of ∼ 4.9 eV and accordingly a corresponding wavelength of ∼ 260 nm, [86][87][88][89][90][91] is naturally suitable for solar-blind UV detection. Consequently, Ga 2 O 3 has attracted much attention recently, and its characteristics of solar-blind UV detection have been demonstrated in various device structures, including MSM structure, Schottky junction, and heterojunction structure.…”

The optical properties of 325 nm AlGaN grown by MBE

“…This wide range covers three distinct ultraviolet (UV) regions, namely UV-A (320-400 nm), UV-B (290-320 nm), and UV-C (200-290 nm) [1,2]. The versatile properties of AlGaN make it highly suitable for various optoelectronic applications, including ultraviolet light-emitting diodes (LEDs), laser diodes (LDs), and solar-blind avalanche photodiodes (APDs) [3][4][5][6]. Moreover, owing to its remarkable two-dimensional electron gas (2DEG) density and mobility, the AlGaN/GaN channel enables the realization of high-power electronic devices for applications in RF power and switching electronics [7][8][9].…”