Thermal stress effects on local electronic properties on N-type GaN crystals in contact with Au/Ti/Cr electrode film by micro-Raman spectroscopy at high temperatures

Kawase, Motoki; Suda, Jun

doi:10.1016/j.vibspec.2021.103331

Cited by 2 publications

(1 citation statement)

References 20 publications

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“…As transistor fabrication processes shrink to the nanometer scale, the gate-all-around field-effect transistor (GAAFET) has emerged as a key technology to address issues such as electrostatic limitations, low carrier mobility, and electron tunneling. The GaN nanowire field-effect transistor (GaN NW FET) characterized by their high-speed electron transmission and saturation velocity properties, hold significant advantages in electronic applications. , However, the intrinsic Joule self-heating effect within the NW channel layer and nonuniform thermal stress generated at local high temperatures , in GaN NW FETs can hinder the performance of high-power devices. Currently, through device size scaling techniques, successful optimization of the channel dimensions of GAA devices has been achieved, finely tuning them to 3 nm .…”

Section: Introductionmentioning

confidence: 99%

Localized Phonon Transport Study of GaN/SiO₂ Core/shell Nanowires under Thermal-Stress Coupling

Chen,

Hu,

Wang

2024

Langmuir

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In order to comprehensively explore the intricate mechanisms of thermo-mechanical interactions, this study employs the molecular dynamics method to investigate the influence of heat flux density, shell thickness and length, as well as stress on the radial interface phonon transport in GaN/SiO2 core/shell nanowire. Additionally, the surface eigenmode decomposition method is employed to analyze the interface phonon dispersion curves. The investigation reveals that with increasing heat flux density, internal thermal stresses intensify, leading to a complex distribution of thermal stresses within the system. Under the influence of thermal stress, the nonlinear acoustic properties interact with phonon scattering, resulting in the pronounced localization of interface phonons. Compressive stress causes an upshift in low-frequency phonons, while tensile stress induces a downward shift in the high-frequency optical branches at the interface. The localized phonon vibrations at the SiO2/GaN interface under nonuniform stress are identified as the primary cause for the abundant presence of nondispersive phonon modes at the radial interface. By elucidating the subtle interplay between lattice vibrations and stress fields, this study offers a novel and profound understanding of thermo-mechanical coupling effects, thereby providing innovative theoretical foundations for the design and performance management of thermoelectric devices.

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Section: Introductionmentioning

confidence: 99%

Localized Phonon Transport Study of GaN/SiO₂ Core/shell Nanowires under Thermal-Stress Coupling

Chen,

Hu,

Wang

2024

Langmuir

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Photoluminescence Emission Efficiency Analysis Methodology by Integrating Raman Spectroscopy of the A₁(LO) and E₂(high) Phonons in a GaInN/GaN Heterostructure

Shwe,

Asaji,

Kimura

et al. 2024

Physica Status Solidi (b)

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Microscopic lattice vibration images of the E2(high) mode (E2H) and another mode of A1(LO) (A1L) or the higher energy branch of LO‐phonon−plasmon coupling mode (LOPC+) in a Ga0.95In0.05N film on a GaN template are obtained by Raman scattering spectroscopy using a 325 nm laser. The increase in temperature by increasing the laser power is obtained from the decrease in the energy of E2H and the theoretical formula comprising two terms based on the mode energy variation of the bulk material and the thermal strain effect. Using the obtained temperature and the energy shift of the LOPC+, the mapping images of the temperature and electron density in the x–y plane are simultaneously obtained. This image provides the spatial variation of photoluminescence (PL) emission efficiency, given as PL intensity per electron. This method enables the quantitative discussion on photo‐emission efficiency even in the regions of low or high carrier density affected by carrier transport. In the investigated area, a region with a lower PL efficiency is found despite a higher electron density and lower temperature increase than the surrounding region. This imaging analysis is feasible in integrating the carrier and thermal energy transports and recombination processes in carrier dynamics study.

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Thermal stress effects on local electronic properties on N-type GaN crystals in contact with Au/Ti/Cr electrode film by micro-Raman spectroscopy at high temperatures

Cited by 2 publications

References 20 publications

Localized Phonon Transport Study of GaN/SiO₂ Core/shell Nanowires under Thermal-Stress Coupling

Localized Phonon Transport Study of GaN/SiO₂ Core/shell Nanowires under Thermal-Stress Coupling

Photoluminescence Emission Efficiency Analysis Methodology by Integrating Raman Spectroscopy of the A₁(LO) and E₂(high) Phonons in a GaInN/GaN Heterostructure

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Thermal stress effects on local electronic properties on N-type GaN crystals in contact with Au/Ti/Cr electrode film by micro-Raman spectroscopy at high temperatures

Cited by 2 publications

References 20 publications

Localized Phonon Transport Study of GaN/SiO2 Core/shell Nanowires under Thermal-Stress Coupling

Localized Phonon Transport Study of GaN/SiO2 Core/shell Nanowires under Thermal-Stress Coupling

Photoluminescence Emission Efficiency Analysis Methodology by Integrating Raman Spectroscopy of the A1(LO) and E2(high) Phonons in a GaInN/GaN Heterostructure

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Localized Phonon Transport Study of GaN/SiO₂ Core/shell Nanowires under Thermal-Stress Coupling

Localized Phonon Transport Study of GaN/SiO₂ Core/shell Nanowires under Thermal-Stress Coupling

Photoluminescence Emission Efficiency Analysis Methodology by Integrating Raman Spectroscopy of the A₁(LO) and E₂(high) Phonons in a GaInN/GaN Heterostructure