Ultrasensitive UV-C detection based on MOCVD-grown highly crystalline ultrawide bandgap orthorhombic κ-Ga2O3

Lim, Namsoo; Min, Jung‐Wook; Min, Jung‐Hong; Kang, Chun Hong; Li, Kuang-Hui; Park, Tae‐Yong; Kim, Woochul; Davaasuren, Bambar; Ng, Tien Khee; Ooi, S. Boon; Woo, Deok Ha; Park, Ji‐Hyeon; Pak, Yusin

doi:10.1016/j.apsusc.2022.155350

Cited by 11 publications

(11 citation statements)

References 31 publications

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“…We assign the smaller value of 𝜏 l /𝜏 t in the thinner layers to a larger carrier recombination rate at the sapphire-GaSe interface and lower mobility of charge carriers. Overall, the properties of these devices compare favorably with UV-sensors from the literature, such as those reported recently for the wide band gap Ga 2 O 3 , [48][49][50] whose frequency band and on/off current ratio are both smaller than in our devices. The large optical absorption of GaSe in the UV-C band (200-280 nm range) and sensitivity to polarization of light provide a platform for advances in this important technological spectral range.…”

Section: Uv-c Sensorssupporting

confidence: 85%

“…This can enable deployment of wide field-of-view receivers for better signal detection and low background noise for non-line-of-sight and line-ofsight communication. [48,50,51] Finally, we note that the two polymorphs, D 3h and D 3d , exhibit similar electronic band structures and densities of states. [42] Thus, both polymorphs are important for UV-C sensing.…”

Section: Uv-c Sensorsmentioning

confidence: 64%

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Wafer‐Scale Two‐Dimensional Semiconductors for Deep UV Sensing

Shiffa,

Dewes,

Bradford

et al. 2023

Small

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Abstract2D semiconductors (2SEM) can transform many sectors, from information and communication technology to healthcare. To date, top‐down approaches to their fabrication, such as exfoliation of bulk crystals by “scotch‐tape,” are widely used, but have limited prospects for precise engineering of functionalities and scalability. Here, a bottom‐up technique based on epitaxy is used to demonstrate high‐quality, wafer‐scale 2SEM based on the wide band gap gallium selenide (GaSe) compound. GaSe layers of well‐defined thickness are developed using a bespoke facility for the epitaxial growth and in situ studies of 2SEM. The dominant centrosymmetry and stacking of the individual van der Waals layers are verified by theory and experiment; their optical anisotropy and resonant absorption in the UV spectrum are exploited for photon sensing in the technological UV‐C spectral range, offering a scalable route to deep‐UV optoelectronics.

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Section: Uv-c Sensorssupporting

confidence: 85%

Section: Uv-c Sensorsmentioning

confidence: 64%

Wafer‐Scale Two‐Dimensional Semiconductors for Deep UV Sensing

Shiffa,

Dewes,

Bradford

et al. 2023

Small

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“…Predominant peaks with 120° intervals could be observed at a rotational angle of Φ, indicating that the α-Ga 2 O 3 films had the same corundum structure. However, we observed very weak peaks in the α-Ga 2 O 3 layer at positions rotated by 60°, which suggests the inclusion of 60° rotational domains. − All investigated samples comprised pure-phase α-Ga 2 O 3 as observed in the XRD 2θ–ω scan.…”

Section: Resultsmentioning

confidence: 77%

Heteroepitaxial Growth of Thick α-Ga₂O₃ Films on Sapphire Substrates by Flow Modulation Epitaxy with Halide Vapor Phase Epitaxy

Lee,

Cha,

Cho

et al. 2023

Crystal Growth & Design

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In this study, halide vapor phase epitaxy with flow modulation epitaxy (FME) was used to grow a 10 μm thick singlecrystalline α-Ga 2 O 3 epilayer on a sapphire substrate. By optimizing the interval time of the gas, highly crystalline thick α-Ga 2 O 3 epitaxial layers can be grown without any cracks. The as-grown α-Ga 2 O 3 was evaluated using scanning electron microscopy and atomic force microscopy to analyze the improvement in the surface morphology and roughness of the epitaxial layer, while X-ray diffraction was used to evaluate the crystallinity. Under optimized O 2 FME conditions, the thick α-Ga 2 O 3 film exhibited a lower full width at half-maximum (fwhm) of 779 arcsec for the (101̅ 4) plane compared to the (101̅ 4) plane fwhm values of 1137 and 925 arcsec obtained for the reference and HCl FME conditions, respectively. The results indicated that the α-Ga 2 O 3 epitaxial layer grown under the O 2 FME conditions exhibited the best quality. This confirms that the current approach to growing high-quality α-Ga 2 O 3 thick films is stable.

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“…Furthermore, there exists an orthorhombic κ-Ga2O3 with a very similar crystal-structure ε-Ga2O3, and they are usually considered as one structure [56,57]. Recently, orthorhombic κ-Ga2O3 has been proven to be stable up to 800-1000 °C, and this makes it suitable for the fabrication of reliable devices such as detectors for UV and X-rays [58][59][60][61]. Monoclinic-phase β-Ga2O3 belongs to the C2/m space group with a densely stacked anion structure.…”

Section: β-Ga 2 O 3 Materialsmentioning

confidence: 99%

A Review of β-Ga2O3 Power Diodes

He,

Zhao,

Huang

et al. 2024

Materials

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As the most stable phase of gallium oxide, β-Ga2O3 can enable high-quality, large-size, low-cost, and controllably doped wafers by the melt method. It also features a bandgap of 4.7–4.9 eV, a critical electric field strength of 8 MV/cm, and a Baliga’s figure of merit (BFOM) of up to 3444, which is 10 and 4 times higher than that of SiC and GaN, respectively, showing great potential for application in power devices. However, the lack of effective p-type Ga2O3 limits the development of bipolar devices. Most research has focused on unipolar devices, with breakthroughs in recent years. This review mainly summarizes the research progress fora different structures of β-Ga2O3 power diodes and gives a brief introduction to their thermal management and circuit applications.

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Ultrasensitive UV-C detection based on MOCVD-grown highly crystalline ultrawide bandgap orthorhombic κ-Ga2O3

Cited by 11 publications

References 31 publications

Wafer‐Scale Two‐Dimensional Semiconductors for Deep UV Sensing

Wafer‐Scale Two‐Dimensional Semiconductors for Deep UV Sensing

Heteroepitaxial Growth of Thick α-Ga₂O₃ Films on Sapphire Substrates by Flow Modulation Epitaxy with Halide Vapor Phase Epitaxy

A Review of β-Ga2O3 Power Diodes

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Ultrasensitive UV-C detection based on MOCVD-grown highly crystalline ultrawide bandgap orthorhombic κ-Ga2O3

Cited by 11 publications

References 31 publications

Wafer‐Scale Two‐Dimensional Semiconductors for Deep UV Sensing

Wafer‐Scale Two‐Dimensional Semiconductors for Deep UV Sensing

Heteroepitaxial Growth of Thick α-Ga2O3 Films on Sapphire Substrates by Flow Modulation Epitaxy with Halide Vapor Phase Epitaxy

A Review of β-Ga2O3 Power Diodes

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Product

Resources

About

Heteroepitaxial Growth of Thick α-Ga₂O₃ Films on Sapphire Substrates by Flow Modulation Epitaxy with Halide Vapor Phase Epitaxy