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InGaN grown on (0001) vicinal surface shows In-content variations depending on the inclination angle. This property leads to polychromatic emission from InGaN quantum well emitters grown on 3D GaN templates. Controlling the 3D shape enables us to tune the emission spectra, which is beneficial for the fabrication of polychromatic, full color light emitters via single-step crystal growth.

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AlGaN/AlGaN channel High Electron Mobility Transistors (HEMTs) are emerging as promising devices for extreme environmental electronics, offering several advantages over traditional AlGaN/GaN channel HEMTs.
In this study, we have suggested the growth challenges and possible solutions of Al-rich AlGaN channel HEMT. To improve the crystal quality and performance of the HEMT, we have introduced novel epitaxial technologies such as the AlN/AlGaN superlattice (SL) structures and pulsed flow growth. In this paper, we suggest and discuss the results of improving the crystal quality and performance of the AlGaN channel HEMT device by the implementation of these new epitaxial technologies.

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Sc-based nitride solid solutions have experienced rapid evolution over the past several years due to unique synergies of ferroelectricity, piezoelectricity, and optical properties. However, many desirable properties, including reduced coercive fields, exceptional piezoelectricity, and substantial optical non-linearity, only manifest significantly in high-ScN-fraction materials. In this work, we discuss the MBE growth of phase-pure monocrystalline ScGaN films up to ScN fractions of nearly 50%. Excellent reduction in coercive fields and enhancement of bipolar cycling endurance are observed. More broadly, these results invigorate development of advanced epitaxial techniques to grow ScGaN, and related Sc-III-nitrides, to the predicted phase transition compositions and beyond.

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GaN HFET structures with AlNP barrier layers grown by MOVPE using phosphine under different growth conditions are compared. The phosphorus content ranges between 2 and 5 at%. X-ray diffraction indicates its incorporation as PAl on anti-site during continuous growth while for modulated growth P is likely on the N site. The electrical properties are similar. A small change at the beginning of modulated growth results in an increase in the charge carrier density from 7.4x1012 to 2.0x1013 cm-2 and the mobility from 650 to 900 cm2/Vs, which is attributed to the unintentional formation of an AlN spacer.

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This study presents the first demonstration of bulk AlₓGa₁₋ₓN crystal growth using the ammonothermal method. Direct growth on GaN seeds and lateral overgrowth on slender seeds were investigated. Structural and optical analyses revealed both axial and lateral crystallization mechanisms, with dislocation-free regions confirmed by X-ray topography and UV imaging. Energy Dispersive Spectroscopy confirmed aluminum incorporation in the range of 5–7 at.%. The influence of aluminum on growth direction and crystallographic plane formation was also analyzed. The results mark a significant advancement toward native bulk AlₓGa₁₋ₓN substrates for high-performance electronic devices.

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While conventional k·p models combined with Schrödinger, Poisson, and drift-diffusion solvers are widely used to study optical transitions, they are computationally expensive. The Localization Landscape (LL) model is used as an alternative, replacing the eigenvalue problem to efficiently capture quantum effects. Using the LL model with Wigner–Weyl formalism, we reproduce emission and absorption spectra trends similar to k·p results but with reduced simulation time. We further analyze the band structure, polarization switching, and carrier confinement under alloy fluctuations and strain. This LL-based method offers a fast and reliable solution for understanding and optimizing UVC LED performance.

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The growth of Aluminum Gallium Nitride (AlxGa1-xN) layers by Halide Vapor Phase Epitaxy (HVPE) on ammonothermal GaN substrates was investigated. Metal chloride precursors were synthesized from high-purity Ga and Al using HCl or Cl₂ in a multi-zone HVPE reactor. The effects of hydrogen admixture and substrate misorientation on morphology, Al incorporation, and structural quality were analyzed. A 60 µm-thick AlxGa1-xN layer with ~10 at.% Al was obtained in a single run. Step-flow morphologies and a considerable Borrmann effect indicated high crystalline quality between cracks caused by seed–layer mismatch. Results demonstrate the potential for producing free-standing AlxGa1-xN substrates.

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