Crossed Ga2O3/SnO2 Multiwire Architecture: A Local Structure Study with Nanometer Resolution

Martı́nez-Criado, Gema; Segura-Ruíz, Jaime; Hung, Chu Manh; Tucoulou, R.; López, I.; Nogales, E.; Méndez, B.; Piqueras, J.

doi:10.1021/nl502156h

Cited by 35 publications

(28 citation statements)

References 57 publications

(84 reference statements)

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“…The change and shifted energies of white-line feature can be attributed mainly to the disordered and different coordination environments 20 . In addition, the negative shift of the adsorption edge occurs with decreased coordination, which can be used as an indicator of the coordination number of O atom in the structure 21 . The Fourier transform EXAFS spectra of Ga K-edge were used to further understand the atomic structure of ZnGa 2 O 4 film.…”

Section: Resultsmentioning

confidence: 99%

Deep-Ultraviolet Photodetectors Based on Epitaxial ZnGa2O4 Thin Films

Tsai

Basu

Huang

et al. 2018

Sci Rep

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A single-crystalline ZnGa2O4 epilayer was successfully grown on c-plane (0001) sapphire substrate by metal-organic chemical vapor deposition. This epilayer was used as a ternary oxide semiconductor for application in high-performance metal–semiconductor–metal photoconductive deep-ultraviolet (DUV) photodetectors (PDs). At a bias of 5 V, the annealed ZnGa2O4 PDs showed better performance with a considerably low dark current of 1 pA, a responsivity of 86.3 A/W, cut-off wavelength of 280 nm, and a high DUV-to-visible discrimination ratio of approximately 107 upon exposure to 230 nm DUV illumination than that of as-grown ZnGa2O4 PDs. The as-grown PDs presented a dark current of 0.5 mA, a responsivity of 2782 A/W at 230 nm, and a photo-to-dark current contrast ratio of approximately one order. The rise time of annealed PDs was 0.5 s, and the relatively quick decay time was 0.7 s. The present results demonstrate that annealing process can reduce the oxygen vacancy defects and be potentially applied in ZnGa2O4 film-based DUV PD devices, which have been rarely reported in previous studies.

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Section: Resultsmentioning

confidence: 99%

Deep-Ultraviolet Photodetectors Based on Epitaxial ZnGa2O4 Thin Films

Tsai

Basu

Huang

et al. 2018

Sci Rep

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“…The anisotropy of monoclinic gallium-oxide crystal lattice leads to the spontaneous growth of microwires by thermal evaporation methods with an optimal aspect ratio for effective light waveguiding. Furthermore, we have previously reported the formation of more-complex morphologies, such as branches or crossed wires, by codoping Ga 2 O 3 with Sn and Cr [43][44][45]. On the other hand, the high crystal quality and smooth lateral-wall surface of Ga 2 O 3 ∶Cr microwires enables some light confinement and we demonstrate Fabry-Perot resonances due to the reflection in their two ends, because of the refractiveindex change between the material and the air [42].…”

Section: Introductionmentioning

confidence: 66%

Modal Analysis of β−Ga2O3:Cr Widely Tunable Luminescent Optical Microcavities

et al. 2018

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Optical microcavities are key elements in many photonic devices, and those based on distributed Bragg reflectors (DBRs) enhance dramatically the end reflectivity, allowing for higher quality factors and finesse values. Besides, they allow for wide wavelength tunability, needed for nano-and microscale light sources to be used as photonic building blocks in the micro-and nanoscale. Understanding the complete behavior of light within the cavity is essential to obtaining an optimized design of properties and optical tunability. In this work, focused ion-beam fabrication of high refractive-index contrast DBR-based optical cavities within Ga 2 O 3 ∶Cr microwires grown and doped by the vapor-solid mechanism is reported. Room-temperature microphotoluminescence spectra show strong modulations from about 650 nm up to beyond 800 nm due to the microcavity resonance modes. Selectivity of the peak wavelength is achieved for two different cavities, demonstrating the tunability of this kind of optical system. Analysis of the confined modes is carried out by an analytical approximation and by finite-difference-time-domain simulations. A good agreement is obtained between the reflectivity values of the DBRs calculated from the experimental resonance spectra, and those obtained by finite-difference-time-domain simulations. Experimental reflectivities up to 70% are observed in the studied wavelength range and cavities, and simulations demonstrate that reflectivities up to about 90% could be reached. Therefore, Ga 2 O 3 ∶Cr high-reflectivity optical microcavities are shown as good candidates for single-material-based, widely tunable light emitters for micro-and nanodevices.

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“…transversal pyramids that grow on the lateral sides of the main rods. It has been previously reported that during vapour-solid (VS) growth the presence of different doping elements in the precursors can result in notable morphological changes, such as the formation of branches [9], crossing wires [17] and complex hierarchical structures [18]. However, these morphological pyramidal features have not been observed with other dopants or in undoped gallium oxide microstructures grown under similar conditions, as shown in figure 1(e).…”

Section: Methodsmentioning

confidence: 93%

Influence of Li doping on the morphology and luminescence of Ga₂O₃microrods grown by a vapor-solid method

López¹,

Alonso-Orts²,

Nogales³

et al. 2016

Semicond. Sci. Technol.

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Gallium oxide microrods have been grown by an evaporation-deposition method by using a precursor containing lithium in order to check the influence of such dopant on the morphology and physical properties of the obtained β-Ga2O3 structures. SEM studies show that the morphology is modified with respect to undoped gallium oxide, promoting the growth of micropyramids transversal to the microwire axis. Raman analysis reveals good crystal quality and an additional Raman peak centred at around 270 cm -1 , characteristic of these samples and not present in undoped monoclinic gallium oxide. The presence of the Li + ions also influences the luminescence emission by inducing a red-shift of the characteristic UV-blue defect band of gallium oxide. In addition, an intense sharp peak centred around 717 nm observed both by cathodoluminescence (CL) and photoluminescence (PL) is also attributed to the presence of these ions. The Li related luminescence features have been also investigated by PL excitation (PLE) spectra and by the temperature dependence of the luminescence.

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Crossed Ga₂O₃/SnO₂ Multiwire Architecture: A Local Structure Study with Nanometer Resolution

Cited by 35 publications

References 57 publications

Deep-Ultraviolet Photodetectors Based on Epitaxial ZnGa2O4 Thin Films

Deep-Ultraviolet Photodetectors Based on Epitaxial ZnGa2O4 Thin Films

Modal Analysis of β−Ga2O3:Cr Widely Tunable Luminescent Optical Microcavities

Influence of Li doping on the morphology and luminescence of Ga₂O₃microrods grown by a vapor-solid method

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Crossed Ga2O3/SnO2 Multiwire Architecture: A Local Structure Study with Nanometer Resolution

Cited by 35 publications

References 57 publications

Deep-Ultraviolet Photodetectors Based on Epitaxial ZnGa2O4 Thin Films

Deep-Ultraviolet Photodetectors Based on Epitaxial ZnGa2O4 Thin Films

Modal Analysis of β−Ga2O3:Cr Widely Tunable Luminescent Optical Microcavities

Influence of Li doping on the morphology and luminescence of Ga2O3microrods grown by a vapor-solid method

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Resources

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Crossed Ga₂O₃/SnO₂ Multiwire Architecture: A Local Structure Study with Nanometer Resolution

Influence of Li doping on the morphology and luminescence of Ga₂O₃microrods grown by a vapor-solid method