Search query: optical phonon scattering mobility

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abstract: Abstract Optical phonon scattering mobility has been calculated using numerical methods, and a general program was developed in Matlab to calculate mobility due to scattering on optical phonons. Calculations were done for InAs material that was irradiated by fast neutrons.
author_names: R Kobaidze

E V Khutsishvili

Nodar Kekelidze
title: Numerical computation of charge carriers optical phonon scattering mobility in III V semiconductor compounds
year: 2018

title: Polar optical phonon scattering mobility in semiconductor quantum wells.
venue: Physical review. B, Condensed matter
year: 1986

abstract: Temperature characteristics of the channel mobility were investigated for 4H SiC trenched MOSFETs in the range from 30 to 200 degC. The conventional model of channel mobility limited by carrier scattering is based on Si MOSFETs and shows a greatly different channel mobility from the experimental value, especially at high temperatures. On the other hand, our improved mobility model taking into account optical phonon scattering yielded results in excellent agreement with experimental results. Moreover, the major factors limiting the channel mobility were found to be Coulomb scattering in a low effective field <0.7 MV/cm) and optical phonon scattering in a high effective field.
author_names: Katsuhiro Kutsuki

Sachiko Kawaji

Yukihiko Watanabe

Toru Onishi

Hirokazu Fujiwara

Kensaku Yamamoto

Toshimasa Kariya Yamamoto
title: Impact of optical phonon scattering on inversion channel mobility in 4H SiC trenched MOSFETs
year: 2017

abstract: High carrier mobility is often invoked to justify the exceptionally long diffusion length in CH3NH3PbI3 perovskites. Using a combination of an ab initio band structure and scattering models, we present clear evidence that large electrical and Hall mobilities are crucially related to the low scattering rate of carriers with polar optical phonons, which represents the dominant mobility limiting mechanism at room temperature. With a charge injection regime at room temperature, we obtained carrier relaxation times (trel) of ~10 fs, which are typical of polar inorganic semiconductors, and electrical mobilities (m) as high as ~60 cm(2) V( 1) s( 1) and 40 cm(2) V( 1) s( 1) for electrons and holes, respectively, which were robustly independent on the injected carrier density in the range of n 10(14) cm( 3) to 10(20) cm( 3) In the absence of a significant concentration of trapping centers, these mobilities foster diffusion lengths of ~10 mm for the low injection density regime (n 10(15) cm( 3) which are in agreement with recent measurements for highly pure single crystal perovskites.
author_names: Alessio Filippetti

Alessandro Mattoni

Claudia Caddeo

Michele Saba

Pietro Delugas
title: Low electron polar optical phonon scattering as a fundamental aspect of carrier mobility in methylammonium lead halide CH3NH3PbI3 perovskites.
venue: Physical chemistry chemical physics PCCP
year: 2016

abstract: Abstract Considering the built in electric fields and the two mode property of transverse optical phonons in AlGaN material, the electronic eigen energies and wave functions are obtained by solving Schrodinger equation with the finite difference method. The dispersion relations and potentials of the optical phonons are given by the transfer matrix method. The mobility of the two dimensional electron gas influenced by the optical phonons in Al2O3/AlGaN/AlN/GaN heterostructures is investigated based on the theory of Lei Ting force balance equation. It is found that the scattering from the half space phonons is the main factor affecting the electronic mobility, and the influence of the other phonons can be ignored. The results show that the mobility decreases with increasing the thicknesses of Al2O3 and AlN layers, but there is no definite relationship between the mobility and the thickness of AlGaN barrier. The mobility is obviously reduced by increasing Al component in AlGaN crystal to show that the effect of ternary mixed crystals is important. It is also found that the mobility increases first and then decreases as the increment of the fixed charges, but decreases always with increasing temperature. The heterostructures constructed here can be good candidates as metal oxide semiconductor high electron mobility transistors since they have higher electronic mobility due to the influence from interface phonons weakened by the AlN interlayer.
author_names: X J Zhou

Y H Qu

S L Ban

Zi Wang
title: Optical phonon scattering on electronic mobility in Al2O3/AlGaN/AlN/GaN heterostructures
year: 2017

abstract: N polar GaN channel mobility is important for high frequency device applications. Here, we report theoretical calculations on the surface optical (SO) phonon scattering rate of two dimensional electron gas (2DEG) in N polar GaN quantum well channels with high k dielectrics. Rode's iterative calculation is used to predict the scattering rate and mobility. Coupling of the GaN plasmon modes with the SO modes is taken into account and dynamic screening is employed under linear polarization response. The effect of SO phonons on 2DEG mobility was found to be small at >5 nm channel thickness. However, the SO mobility in 3 nm N polar GaN channels with HfO2 and ZrO2 high k dielectrics is low and limits the total mobility. The SO scattering for SiN dielectric on GaN was found to be negligible due to its high SO phonon energy. Using Al2O3, the SO phonon scattering does not affect mobility significantly only except the case when the channel is too thin with a low 2DEG density.
author_names: Krishnendu Ghosh

Uttam Singisetti
title: Rode's iterative calculation of surface optical phonon scattering limited electron mobility in N polar GaN devices
year: 2015

abstract: Atomically thin Bi2 O2 Se has emerged as a new member in 2D materials with ultrahigh carrier mobility and excellent air stability, showing great potential for electronics and optoelectronics. In addition, its ferroelectric nature renders an ultralow thermal conductivity, making it a perfect candidate for thermoelectrics. In this work, the thermoelectric performance of 2D Bi2 O2 Se is investigated over a wide temperature range (20 300 K) A gate tunable transition from polar optical phonon (POP) scattering to piezoelectric scattering is observed, which facilitates the capacity of drastic mobility engineering in 2D Bi2 O2 Se. Consequently, a high power factor of more than 400 uW m 1 K 2 over an unprecedented temperature range (80 200 K) is achieved, corresponding to the persistently high mobility arising from the highly gate tunable scattering mechanism. This finding provides a new avenue for maximizing thermoelectric performance by changing the scattering mechanism and carrier mobility over a wide temperature range.
author_names: Fang Yang

Jing Wu

Ady Suwardi

Yunshan Zhao

Boyuan Liang

Jie Jiang

Jianwei Xu

Dongzhi Chi

Kedar Hippalgaonkar

Junpeng Lu

Zhenhua Ni
title: Gate Tunable Polar Optical Phonon to Piezoelectric Scattering in Few Layer Bi2 O2 Se for High Performance Thermoelectrics.
venue: Advanced materials
year: 2020

abstract: Cubic perovskite oxides are emerging high mobility transparent conducting oxides (TCOs) but Ge based TCOs had not been known until the discovery of metastable cubic SrGeO$_3$ $0.5 \times 0.4 \times 0.2$ mm$^3$ large single crystals of the cubic SrGeO$_3$ perovskite were successfully synthesized employing the high pressure flux method. The phonon spectrum is determined from the IR optical reflectance and Raman scattering analysis to evaluate the electron transport governed by optical phonon scattering. A calculated room temperature mobility on the order of $3.9 \times 10^2$ cm$^2$V$ 1}$s$ 1} is obtained, identifying cubic SrGeO$_3$ as one of the most promising TCOs. Employing classical phonon theory and a combined experimental theoretical approach, a comprehensive analysis of the intrinsic electron mobility in the cubic perovskite semiconductors SrGeO$_3$ BaSnO$_3$ and SrTiO$_3$ is provided based on the magnitude of polarization and eigenfrequency of optically active phonons.
author_names: Christian A Niedermeier

Yu Kumagai

Keisuke Ide

Takayoshi Katase

Fumiyasu Oba

Hideo Hosono

Toshio Kamiya
title: Phonon scattering limited mobility in the representative cubic perovskite semiconductors SrGeO3 BaSnO3 and SrTiO3
year: 2020

abstract: Abstract The effects of substrate on the electronic properties of Graphene remains unclear. Many theoretical and experimental efforts have been done to clarify this discrepancy. In this work, we studied the electronic transport in armchair Graphene nanoribbons (AGNR) in the presence of substrate's disorder. The three main substrate's disorders surface roughness, charged impurity and surface optical phonon are investigated. Non Equilibrium Green's function along with the tight binding model is employed to investigate the electronic properties of Graphene Nanoribbons. The effects of these disorders are investigated individually, finally, the effects of them are compared to determine the dominant source of scattering.
author_names: Shoeib Babaee Touski

Manouchehr Hosseini
title: A comparative study of substrates disorder on mobility in the Graphene nanoribbon: Charged impurity, surface optical phonon, surface roughness
year: 2020

abstract: We study the electrical and optical properties of degenerate ZnGa2O4 films grown by metalorganic chemical vapor deposition (MOCVD) on sapphire and semi insulating films grown by pulsed laser deposition (PLD) on fused silica. After a forming gas anneal at 700 degC, the MOCVD film is highly conducting, with a room temperature carrier concentration of 2 x 1020 cm 3, a mobility of 20 cm2/V s, and direct bandgap absorptions at 3.65 eV and 4.60 eV. Under the same annealing conditions, the PLD film is semi insulating, with a direct bandgap absorption at 5.25 eV. The phonon structure, important for electrical and thermal conduction as well as superconductivity and other quantum phenomena, is very complicated due to the large number of atoms (and, thus, phonon branches) in the unit cell. However, we show that the phonon contributions to electron mobility (mph) can be directly measured by quantum based magnetoconductivity over the temperature span T 10 200 K. From an approximate analytical formula, mph function (Tph, T) we calculate an effective phonon energy kTph(T) that takes account of all phonon contributions at temperature T. For T 10 200 K, the value of kTph ranges from about 10 to 90 meV, consistent with the energy range of the ZnGa2O4 phonon density of states (at 0 K) calculated by density functional theory. The total measured mobility can then be modeled by mtot 1 mii 1 mph 1, where mii is the mobility due to ionized impurity scattering. With a high bandgap, controllable conductivity, high breakdown voltage, and bulk growth capability, ZnGa2O4 offers opportunities for high power electronics and UV detectors.
author_names: David C Look

Kevin D Leedy

Ray-Hua Horng

Marco D Santia

Stefan C Badescu
title: Electrical and optical properties of degenerate and semi insulating ZnGa2O4: Electron/phonon scattering elucidated by quantum magnetoconductivity
year: 2020