A two-step in situ measurement method for temperature and thermal stress of power device based on a single Raman peak

Li, Yupu; Fan, Aoran; Zhang, Xiaoyu; Zhang, Xing

doi:10.1016/j.ijheatmasstransfer.2023.124555

Cited by 4 publications

(2 citation statements)

References 36 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/SiO₂Core/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/SiO₂Core/shell Nanowires under Thermal-Stress Coupling

Chen,

Hu,

Wang

2024

Langmuir

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“…Alternatively, Raman spectroscopy provides the capability to measure the temperature and pressure of fluid-lubricated films. Raman spectra contain the vibrational energy of the sample, which is affected by changes in temperature and pressure, thus offering the possibility of temperature and pressure measurements [15,16]. Jubault et al [17] used a coupled sphere/flat surface device and a Raman microphotometer to measure the pressure distribution of a model lubricant that occurs in a rolling EHD contact.…”

Section: Introductionmentioning

confidence: 99%

Green-Emitting Carbon Quantum Dots: Highly Sensitive Temperature Sensing Probe in Nanocomposite and Lubrication System

Sun,

Yan,

Zhang

et al. 2024

Lubricants

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Carbon quantum dots (CQDs) have already demonstrated their utility as lubricant additives, and non-contact temperature sensing based on CQDs offers considerable potential for condition monitoring in mechanical, electrical, and other fields, as well as lubrication-temperature multifunctional applications in lubricants. In this paper, we have successfully synthesized and designed high-brightness carbon quantum dots/polyvinyl alcohol (PVA) temperature sensor thin film and dispersions of CQDs in a liquid paraffin lubrication system. Based on fluorescence intensity and the fluorescence intensity ratio, the carbon quantum dot/PVA film exhibited exponential temperature-dependent properties with a wide applicability range, a high goodness of fit (R2 > 0.99), and high relative thermal sensitivity (relative sensitivities of 1.74% K−1 and 1.39% K−1 for fluorescence intensity and fluorescence intensity ratio, respectively). In addition, based on the fluorescence intensity, the CQDs exhibited a wide temperature range (20–90 °C), a high goodness of fit (R2 > 0.99), and higher sensitivity (2.84% K−1) in a liquid paraffin lubrication system, which reflects the temperature responsive properties of carbon quantum dots as additives in lubrication systems. These findings provide convenient and effective possibilities for the sensing and monitoring of carbon quantum dots and their multifunctional applications under lubrication systems.

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Thermal stress concentration points and stress mutations in nano-multilayer film structures

Zheng,

Wang,

Song

et al. 2024

Commun. Theor. Phys.

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In the multilayer film-substrate system, thermal stress concentration and stress mutations cause film buckling, delamination and cracking, leading to device failure. In this paper, we investigated a multilayer film system composed of a substrate and three film layers. The thermal stress distribution inside the structure was calculated by the finite element method, revealing significant thermal stress differences between the layers. This is mainly due to the mismatch of the coefficient of thermal expansion between materials. Different materials respond differently to changes in external temperature, leading to compression between layers. There are obvious thermal stress concentration points at the corners of the base layer and the transition layer, which is due to the sudden change of the shape at the geometric section of the structure, resulting in a sudden increase in local stress. To address this issue, we chamfered the substrate and added an intermediate layer between the substrate and the transition layer to assess whether these modifications could reduce or eliminate the thermal stress concentration points and extend the service life of the multilayer structure. The results indicate that chamfering and adding the intermediate layer effectively reduce stress discontinuities and mitigate thermal stress concentration points, thereby improving interlayer bonding strength.

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A two-step in situ measurement method for temperature and thermal stress of power device based on a single Raman peak

Cited by 4 publications

References 36 publications

Localized Phonon Transport Study of GaN/SiO₂Core/shell Nanowires under Thermal-Stress Coupling

Localized Phonon Transport Study of GaN/SiO₂Core/shell Nanowires under Thermal-Stress Coupling

Green-Emitting Carbon Quantum Dots: Highly Sensitive Temperature Sensing Probe in Nanocomposite and Lubrication System

Thermal stress concentration points and stress mutations in nano-multilayer film structures

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A two-step in situ measurement method for temperature and thermal stress of power device based on a single Raman peak

Cited by 4 publications

References 36 publications

Localized Phonon Transport Study of GaN/SiO2Core/shell Nanowires under Thermal-Stress Coupling

Localized Phonon Transport Study of GaN/SiO2Core/shell Nanowires under Thermal-Stress Coupling

Green-Emitting Carbon Quantum Dots: Highly Sensitive Temperature Sensing Probe in Nanocomposite and Lubrication System

Thermal stress concentration points and stress mutations in nano-multilayer film structures

Contact Info

Product

Resources

About

Localized Phonon Transport Study of GaN/SiO₂Core/shell Nanowires under Thermal-Stress Coupling

Localized Phonon Transport Study of GaN/SiO₂Core/shell Nanowires under Thermal-Stress Coupling