Performance enhancement of ZnGa2O4 Schottky type deep-ultraviolet photodetectors by oxygen supercritical fluid treatment

Sood, Apoorva; Tarntair, Fow Gow; Wang, Yu Xuan; Chang, Ting Chang; Chen, Yu-Hsuan; Liu, Po−Liang; Horng, Ray Hua

doi:10.1016/j.rinp.2021.104764

Cited by 18 publications

(2 citation statements)

References 36 publications

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“…ZGO is also a promising long-lasting brilliant phosphor that can be used for in vivo imaging by thermally driven luminescence and x-ray phosphorescence when doped with transition metal elements. [14][15][16] ZGO is frequently studied in polycrystalline and nanopowder materials, and Galazka et al discovered its easily adjustable electrical conductivity and reported the successful development of a single crystal high-quality bulk material. 17 With a free electron concentration of ∼10 20 /cm 3 and a Hall electron mobility of ∼107 cm 2 /V s at such high carrier concentrations, melt-grown ZGO crystals can be either conductive or made electrically insulating by Al doping.…”

Section: Introductionmentioning

confidence: 99%

Growth optimization, optical, and dielectric properties of heteroepitaxially grown ultrawide-bandgap ZnGa2O4 (111) thin film

Karmakar,

Emu,

Halim

et al. 2024

Journal of Applied Physics

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Ultrawide bandgap ZnGa2O4 (ZGO) thin films were grown on sapphire (0001) substrates at various growth temperatures with a perspective to investigate the electrical and optical characteristics required for high-power electronic applications. Due to the variation in the vapor pressure of Zn and Ga, severe loss of Zn was observed during pulsed laser deposition, which was solved by using a zinc-rich Zn0.98Ga0.02O target. A pure phase single-crystalline ZGO thin film was obtained at a deposition temperature of 750 °C and an oxygen pressure of 1 × 10−2 Torr. The out-of-plane epitaxial relationship between the sapphire and ZGO thin film was obtained from φ-scan. The x-ray rocking curve of the ZGO thin film grown at 750 °C exhibits a full width at half maximum of ∼0.098°, which indicates a good crystalline phase and quality of the thin film. Core-level x-ray photoelectron spectroscopy of ZGO grown at 750 °C indicated that Zn and Ga were in the 2+ and 3+ oxidation states, respectively, and the atomic ratio of Zn/Ga was estimated to be ∼0.48 from the fitted values of Zn-2p3/2 and Ga-2p3/2. The high-resolution transmission electron microscopy images revealed a sharp interface with the thickness of the ZGO film of ∼265 nm, and the signature of minor secondary phases was observed. The bandgap of the ZGO film at different growth temperatures was calculated from the ultraviolet-diffuse reflectance spectroscopy spectra, and its value was obtained to be ∼5.08 eV for the 750 °C grown sample. The refractive index (n) and the extinction coefficient (k) were determined to be ∼1.94 and 0.023 from the ellipsometric data, respectively, and the real dielectric function (ɛr) was estimated to be ∼6.8 at energy 5 eV. The ultrawide bandgap and dielectric function of ZGO recommend its possible potential applications in deep-ultraviolet optoelectronic devices and high-power electronics.

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Section: Introductionmentioning

confidence: 99%

Growth optimization, optical, and dielectric properties of heteroepitaxially grown ultrawide-bandgap ZnGa2O4 (111) thin film

Karmakar,

Emu,

Halim

et al. 2024

Journal of Applied Physics

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“…semiconductor platform for applications such as photonics (i.e. photodetector [2], phototransistors [3][4][5], gas sensors [6], thin-film-transistors [7][8][9], or optical memory application [10]), thus, heralding novel spinel electronics. Spinel oxides have, indeed, a peculiar chemical formula AB 2 O 4 , where A and B cations occupy octahedral and tetrahedral sites formed by oxygen atoms.…”

Section: Introductionmentioning

confidence: 99%

Assessment of large critical electric field in ultra-wide bandgap p-type spinel ZnGa₂O₄

Chi

Tchelidze

Sartel

et al. 2023

J. Phys. D: Appl. Phys.

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The spinel Zinc Gallate ZnGa2O4 stands out among the emerging ultra-wide bandgap (~5eV) semiconductors as the ternary complex oxide with the widest gap where bipolar conductivity (electrons and holes) has been demonstrated. For power and energy electronic applications, a fundamental property of the material is its critical electric field (Ec), as, for example, the Baliga’s figure of merit scales as ~Ec3. However, the critical electric field of ZnGa2O4 is yet unknown. In this work, it is carried out with the thermodynamic analysis of point defects and free carriers versus oxygen pressure. According to this analysis, highly resistive p--type ZnGa2O4 thin films on sapphire and Si substrates were elaborated by metal organic chemical vapor deposition (MOCVD) technique. Hall Effect measurements confirmed a low carrier level at room temperature (estimated at 1011 cm-3), and breakdown voltage characterizations on a polycrystalline thin film on p--type doped silicon substrates have been performed. We can deduce a value of the critical electric field to be at least 5.3 MV/cm for p--type ZnGa2O4.

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Near‐Infrared Mechanoluminescence from Cr³⁺‐Doped Spinel Nanoparticles for Potential Oral Diseases Detection

Shao,

Chen,

Lun

et al. 2024

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Mechanoluminescence (ML) phosphors have found various promising utilizations such as in non‐destructive stress sensing, anti‐counterfeiting, and bio stress imaging. However, the reported NIR MLs have predominantly been limited to bulky particle size and weak ML intensity, hindering the further practical applications. For this regard, a nano‐sized ZnGa2O4: Cr3+ NIR ML phosphor is synthesized by hydrothermal method. By improving the synthesis method and regulating the chemical composition, the NIR ML (600–1000 nm) intensity of such nano‐materials has been further enhanced about four times. The reasons for the ML performance difference between micro‐/nano‐ sized phosphors also have been preliminarily analyzed. Additionally, this work probes into the ML mechanism deeply in traps’ aspect from band structure and defect formation energy, which can supply significant references for a new approach to develop efficient NIR ML nanoparticles. Finally, due to excellent tissue penetration capability, nano‐sized ZnGa2O4:Cr3+ NIR ML phosphor shows great potential applications in biomedical fields such as for the detection of clinical oral diseases.

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Performance enhancement of ZnGa2O4 Schottky type deep-ultraviolet photodetectors by oxygen supercritical fluid treatment

Cited by 18 publications

References 36 publications

Growth optimization, optical, and dielectric properties of heteroepitaxially grown ultrawide-bandgap ZnGa2O4 (111) thin film

Growth optimization, optical, and dielectric properties of heteroepitaxially grown ultrawide-bandgap ZnGa2O4 (111) thin film

Assessment of large critical electric field in ultra-wide bandgap p-type spinel ZnGa₂O₄

Near‐Infrared Mechanoluminescence from Cr³⁺‐Doped Spinel Nanoparticles for Potential Oral Diseases Detection

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Performance enhancement of ZnGa2O4 Schottky type deep-ultraviolet photodetectors by oxygen supercritical fluid treatment

Cited by 18 publications

References 36 publications

Growth optimization, optical, and dielectric properties of heteroepitaxially grown ultrawide-bandgap ZnGa2O4 (111) thin film

Growth optimization, optical, and dielectric properties of heteroepitaxially grown ultrawide-bandgap ZnGa2O4 (111) thin film

Assessment of large critical electric field in ultra-wide bandgap p-type spinel ZnGa2O4

Near‐Infrared Mechanoluminescence from Cr3+‐Doped Spinel Nanoparticles for Potential Oral Diseases Detection

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Assessment of large critical electric field in ultra-wide bandgap p-type spinel ZnGa₂O₄

Near‐Infrared Mechanoluminescence from Cr³⁺‐Doped Spinel Nanoparticles for Potential Oral Diseases Detection