Relative importance of phonon scattering to carrier mobility in Si surface layer at room temperature

1973 ◽  
Vol 44 (8) ◽  
pp. 3619-3625 ◽  
Author(s):  
Y. C. Cheng ◽  
E. A. Sullivan
Keyword(s):  
Surface Layer ◽  
Carrier Mobility ◽  
Room Temperature ◽  
Phonon Scattering ◽  
Relative Importance

scholarly journals Prediction of higher thermoelectric performance in BiOCuSe by weakening electron-polar optical phonon scattering

2020 ◽  
Author(s):  
Tianqi Zhao ◽  
Quinn Gibson ◽  
Luke Daniels ◽  
Ben Slater ◽  
Furio Cora
Keyword(s):  
Carrier Mobility ◽  
Figure Of Merit ◽  
Room Temperature ◽  
Phonon Scattering ◽  
Hole Mobility ◽  
Polar Optical Phonon ◽  
First Principles Calculations ◽  
Thermoelectric Figure ◽  
Optical Phonon Scattering ◽  
Electron Phonon Scattering

Abstract BiOCuSe is a promising thermoelectric material, but its applications are hindered by low carrier mobility. We use first principles calculations to analyse electron-phonon scattering mechanisms and evaluate their contributions to the thermoelectric figure of merit ZT. The combined scattering of carriers by polar optical (PO) and longitudinal acoustic (LA) phonons yields an intrinsic hole mobility of 32 cm2 V-1 s-1 at room temperature and a temperature power law of T-1.5, which agree well with experiments. We demonstrate that electron phonon scattering in the Cu-Se layer dominates at low T, while contributions from the Bi-O layer become increasingly significant at higher T. At room temperature, ZT is calculated to be 0.48 and can be improved by 30% through weakening PO phonon scattering in the Cu-Se layer. This finding agrees with the experimental observation that weakening the carrier-phonon interaction by Te substitution in the Cu-Se layer improves mobility and ZT. At high T, the figure of merit is improved by weakening phonon scattering in the Bi-O layer instead. The theoretical ZT limit of BiOCuSe is calculated to be 2.5 at 875 K.

Performance of Surface Carrier Mobility for Nano-Node Strained (110) MOSFETs with Temperature Effect

2011 ◽  
Vol 291-294 ◽  
pp. 3131-3134
Author(s):  
Mu Chun Wang ◽  
Hsin Chia Yang ◽  
Wen Shiang Liao
Keyword(s):  
Mass Production ◽  
Carrier Mobility ◽  
Room Temperature ◽  
Phonon Scattering ◽  
Short Channel ◽  
Channel Mobility ◽  
Temperature Impact ◽  
Control Devices ◽  
And Control ◽  
Long Channel

Considering the increase of the driving current for nano-node MOSFET devices, source/drain (S/D) site etched and refilled with SiGe material is a promising process to promote the channel mobility due to the tensile or compressive effect. Using SiGe-S/D process comparing the performance with Si-S/D and control devices on (110) wafer to probe the nano-scale mass-production possibility is a good integration. Besides the discussion in the room temperature, the device characteristics with temperature dependence are more impressive. Through analysis for the cumulated data, the temperature impact in the performance of long channel MOSFETs is higher than that in the short channel ones. The phenomena can be attributed to the tensile or compressive effect to n- or p-MOSFETs with phonon scattering disturbance.

Polar Optical Phonon Instability and Intervalley Transfer in Gallium Nitride

1998 ◽  
Vol 512 ◽  
Author(s):  
B. E. Foutz ◽  
S. K. O'leary ◽  
M. S. Shur ◽  
L. F. Eastman ◽  
B. L. Gelmont ◽  
...  
Keyword(s):  
Gallium Nitride ◽  
Analytical Model ◽  
Optical Phonon ◽  
Room Temperature ◽  
Phonon Scattering ◽  
Polar Optical Phonon ◽  
Scattering Mechanism ◽  
Loss Mechanism ◽  
One Dimensional ◽  
Optical Phonon Scattering

ABSTRACTWe develop a simple, one-dimensional, analytical model, which describes electron transport in gallium nitride. We focus on the polar optical phonon scattering mechanism, as this is the dominant energy loss mechanism at room temperature. Equating the power gained from the field with that lost through scattering, we demonstrate that beyond a critical electric field, 114 kV/cm at T = 300 K, the power gained from the field exceeds that lost due to polar optical phonon scattering. This polar optical phonon instability leads to a dramatic increase in the electron energy, this being responsible for the onset of intervalley transitions. The predictions of our analytical model are compared with those of Monte Carlo simulations, and are found to be in satisfactory agreement.

Room-temperature discotic liquid-crystalline coronene diimides exhibiting high charge-carrier mobility in air

2009 ◽  
Vol 19 (37) ◽  
pp. 6688 ◽  
Author(s):  
Zesheng An ◽  
Junsheng Yu ◽  
Benoit Domercq ◽  
Simon C. Jones ◽  
Stephen Barlow ◽  
...  
Keyword(s):  
Charge Carrier ◽  
Carrier Mobility ◽  
Liquid Crystalline ◽  
Room Temperature ◽  
Charge Carrier Mobility ◽  
High Charge ◽  
High Charge Carrier Mobility

Electric and thermoelectric properties of CdTe/PbTe epitaxial nanocomposite

2014 ◽  
Vol 07 (06) ◽  
pp. 1440007
Author(s):  
Michal Szot ◽  
Krzysztof Dybko ◽  
Piotr Dziawa ◽  
Leszek Kowalczyk ◽  
Viktor Domukhovski ◽  
...  
Keyword(s):  
Thermoelectric Properties ◽  
Carrier Mobility ◽  
Room Temperature ◽  
Molecular Beam ◽  
High Quality ◽  
Polycrystalline Solid ◽  
Hall Effect Measurements ◽  
Shubnikov De Haas Oscillations

The electric and thermoelectric properties of novel, CdTe / PbTe layered nanocomposite material are investigated. The molecular beam epitaxy (MBE) method was used for preparation of samples with well controlled distances (from 20 to 70 nm) between the layers of CdTe nanograins embedded in PbTe thermoelectric matrix as well as with number of these layers from 2 to 10. The Hall effect measurements performed in temperature range from 4–300 K revealed that carrier mobility is strongly affected by scattering on CdTe grain boundaries. The observation of Shubnikov-de Haas oscillations confirms high quality of the samples and allows determination of effective mass of conducting electrons m* = 0.04m0. The measurements of the room temperature Seebeck coefficient together with electrical conductivity lead to the power factors which are comparable to those reported in PbTe / CdTe polycrystalline solid solutions.

scholarly journals Подвижность ионных носителей заряда в пьезоэлектрических кристаллах Li-=SUB=-2-=/SUB=-B-=SUB=-4-=/SUB=-O-=SUB=-7-=/SUB=-

2020 ◽  
Vol 62 (3) ◽  
pp. 386
Author(s):  
Н.И. Сорокин ◽  
Ю.В. Писаревский ◽  
В.В. Гребенев ◽  
В.А. Ломонов
Keyword(s):  
Crystal Lattice ◽  
Carrier Mobility ◽  
Room Temperature ◽  
Lithium Ion ◽  
Structural Data ◽  
Crystallographic Axis ◽  
Frequency Range ◽  
Impedance Measurements ◽  
Structural Mechanism ◽  
Ag Electrodes

The impedance measurements of Li2B4O7 single crystal with Ag electrodes in the frequency range 1-3*107 Hz at room temperature have been made. The Li2B4O7 crystal (sp. gr. I41cd, Z = 8) was oriented along crystallographic axis c. Contributions from the bulk crystal and crystal / electrode boundaries in the impedance hodograph of the Ag | Li2B4O7 | Ag system were selected. The structural mechanism of lithium-ion transport in Li2B4O7 has been discussed. Based on electrophysical and structural data, the conductivity σdc = 2.3 × 10–9 S / cm, carrier mobility (vacancies VLi) μmob = 6 × 10−10 cm2 / sV and their concentration nmob = 2.4 × 1019 cm – 3 (0.14% of the amount of lithium in the crystal lattice) have been determined.

scholarly journals Phonons, electrons and thermal transport in Planckian high Tc materials

2021 ◽  
Vol 6 (1) ◽  
Author(s):  
Connie H. Mousatov ◽  
Sean A. Hartnoll
Keyword(s):  
Thermal Diffusivity ◽  
Room Temperature ◽  
Phonon Scattering ◽  
Temperature Phase ◽  
Temperature Derivative ◽  
High Tc ◽  
Optimal Doping ◽  
Strong Scattering ◽  
Measured Strength ◽  
Temperature Phase Diagram

AbstractThe room-temperature thermal diffusivity of high Tc materials is dominated by phonons. This allows the scattering of phonons by electrons to be discerned. We argue that the measured strength of this scattering suggests a converse Planckian scattering of electrons by phonons across the room-temperature phase diagram of these materials. Consistent with this conclusion, the temperature derivative of the resistivity of strongly overdoped cuprates is noted to show a kink at a little below 200 K that we argue should be understood as the onset of a high-temperature Planckian T-linear scattering of electrons by classical phonons. This kink continuously disappears toward optimal doping, even while strong scattering of phonons by electrons remains visible in the thermal diffusivity, sharpening the long-standing puzzle of the lack of a feature in the T-linear resistivity at optimal doping associated with the onset of phonon scattering.

Glass-Oxide Nanocomposites as Effective Thermal Insulation Materials

2013 ◽  
Vol 1558 ◽  
Author(s):  
Qing Hao ◽  
Minqing Li ◽  
Garrett Joseph Coleman ◽  
Qiang Li ◽  
Pierre Lucas
Keyword(s):  
Thermal Conductivity ◽  
Thermal Insulation ◽  
Room Temperature ◽  
Phonon Scattering ◽  
Material Composition ◽  
Insulation Materials ◽  
Atomic Structures ◽  
Porous Nanocomposites ◽  
Theoretical Minimum

ABSTRACTWith extremely disordered atomic structures, a glass possesses a thermal conductivity k that approaches the theoretical minimum of its composition, known as the Einstein’s limit.1 Depending on the material composition and the extent of disorder, the thermal conductivity of some glasses can be down to 0.1-0.3 W/m∙K at room temperature,2,3 representing some of the lowest k values among existing solids. Such a low k can be further reduced by the interfacial phonon scattering within a nanocomposite that can be used for thermal insulation applications. In this work, nanocomposites hot pressed from the mixture of glass nanopowder (GeSe4 or Ge20Te70Se10) and commercial SiO2 nanoparticles, or pure glass nanopowder, are investigated for the potential k reduction. It is found that adding SiO2 nanoparticles will instead increase k if the measured k values for usually porous nanocomposites are converted into those for the corresponding solid (kSolid) with Eucken’s formula. In contrast, pure glass nano-samples always show kSolid data significantly reduced from that for the starting glass. For a pure GeSe4 nano-sample, kSolid would beat the Einstein’s limit for its composition.

scholarly journals Remote Phonon Scattering in Two-Dimensional InSe FETs with High-κ Gate Stack

Micromachines ◽  
2018 ◽  
Vol 9 (12) ◽  
pp. 674 ◽  
Author(s):  
Pengying Chang ◽  
Xiaoyan Liu ◽  
Fei Liu ◽  
Gang Du
Keyword(s):  
Quantum Confinement ◽  
Carrier Mobility ◽  
Gate Dielectric ◽  
Phonon Scattering ◽  
Field Effect Transistors ◽  
Temperature Inversion ◽  
Two Dimensional ◽  
Mass Approximation ◽  
Mobility Degradation ◽  
Dual Gate

This work focuses on the effect of remote phonon arising from the substrate and high-κ gate dielectric on electron mobility in two-dimensional (2D) InSe field-effect transistors (FETs). The electrostatic characteristic under quantum confinement is derived by self-consistently solving the Poisson and Schrödinger equations using the effective mass approximation. Then mobility is calculated by the Kubo–Greenwood formula accounting for the remote phonon scattering (RPS) as well as the intrinsic phonon scatterings, including the acoustic phonon, homopolar phonon, optical phonon scatterings, and Fröhlich interaction. Using the above method, the mobility degradation due to remote phonon is comprehensively explored in single- and dual-gate InSe FETs utilizing SiO2, Al2O3, and HfO2 as gate dielectric respectively. We unveil the origin of temperature, inversion density, and thickness dependence of carrier mobility. Simulations indicate that remote phonon and Fröhlich interaction plays a comparatively major role in determining the electron transport in InSe. Mobility is more severely degraded by remote phonon of HfO2 dielectric than Al2O3 and SiO2 dielectric, which can be effectively insulated by introducing a SiO2 interfacial layer between the high-κ dielectric and InSe. Due to its smaller in-plane and quantization effective masses, mobility begins to increase at higher density as carriers become degenerate, and mobility degradation with a reduced layer number is much stronger in InSe compared with MoS2.

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