Catalyst‐Free Vapor–Solid Deposition Growth of β‐Ga₂O₃ Nanowires for DUV Photodetector and Image Sensor Application

Abstract

Photodetection in the solar‐blind deep‐ultraviolet (DUV) regime (200–280 nm) has received significant attention for its many critical applications in military and civil areas. In this study, a vapor–solid synthesis technique for catalyst‐free growth of single‐crystalline β‐Ga2O3 nanowires is developed. A photodetector made of the nanowires is highly sensitive to 265 nm DUV illumination with excellent photoresponse performance. The performance parameters including Ilight/Idark ratio, responsivity, specific detectivity and response speed can attain ≈103, ≈233 A W−1, ≈8.16 × 1012 Jones, and 0.48/0.04 s, respectively. Additionally, the detector has an abrupt response cutoff wavelength at ≈290 nm with a reasonable DUV/visible (250–405 nm) rejection ratio exceeding 102. It is also found that the device can operate properly at a large applied bias of 200 V with the responsivity being enhanced to as high as ≈1680 A W−1. Moreover, such a nanowires‐based photodetector can function as a DUV light image sensor with a reasonable spatial resolution. Holding the above advantages, the present DUV photodetector based on catalyst‐free grown β‐Ga2O3 nanowires possesses huge possibility for application in future DUV optoelectronics.

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

“…The bandgap value is determined by the absorption spectrum obtained using ultraviolet–visible (UV–vis) spectrophotometry. ,, As shown in Figure a,b, the bandgap values of ITO is determined to 3.59 eV by the Tauc plot method, while that of a-Ga 2 O 3 is 5.05 eV. The absorption spectrum shown in Figure b was measured using a-Ga 2 O 3 film grown on sapphire substrate with identical growth conditions.…”

Highly sensitive solar-blind deep ultraviolet photodetector based on graphene/PtSe2/β-Ga2O3 2D/3D Schottky junction with ultrafast speed

“…So far, although a range of Ga2O3 nanostructures (e.g. nanowires, nanofilms, nanosheets, and nanobelts) have been studied to achieve high-performance DUV photodetectors with different geometries [12][13][14][15]. The slow operation speed and modest specific detectivity are obvious disadvantages for a majority of Ga2O3-nanostructuresbased photodetectors operating in the photoconductive mode, impeding the actualization of high-sensitivity and fast-response solar-blind photodetection [14].…”

“…nanowires, nanofilms, nanosheets, and nanobelts) have been studied to achieve high-performance DUV photodetectors with different geometries [12][13][14][15]. The slow operation speed and modest specific detectivity are obvious disadvantages for a majority of Ga2O3-nanostructuresbased photodetectors operating in the photoconductive mode, impeding the actualization of high-sensitivity and fast-response solar-blind photodetection [14]. To circumvent these issues, an emerging important technique combining Ga2O3 with all kinds of materials including graphene, SiC, ZnO, and GaN for the development of functional junction devices has been successfully and extensively adopted to further enhance device performances (e.g.…”

“…fast response, high responsivity, and large specific detectivity), which has been proved to be the most effective approach that also comes along with a simple preparation process [7,12,16,17]. For instance, benefiting from the avalanche multiplication effect, the as-assembled ZnO-Ga2O3 core-shell heterojunction photodetector exhibits a large responsivity (R) of ~ 1.3 × 10 3 A/W, an ultrahigh specific detectivity (D*) up to ~ 9.91 ×10 14 Jones, and a fast response speed shorter than 20 μs [13]. In addition, by constructing graphene (Gr)/Ga2O3 heterostructure, a high responsivity (12.8 A/W at 6 V, 39.3 A/W at 20 V) was achieved at large bias voltages [7,18].…”

A Selective Etching Route for Large-Scale Fabrication of β-Ga2O3 Micro-/Nanotube Arrays

“…It has a wide bandgap (~4.9 eV at room temperature), a high expected breakdown electric field (8 MV/cm), great thermal and chemical stability. In recent years, β-Ga 2 O 3 micro-/nanostructures have exhibited technological potential in many device applications, such as field-effect transistors [1][2][3][4], photodetectors [5][6][7], gas sensors [8][9][10], solar cells [11], and nanophotonic switches [12].…”