First-principles Prediction of Carrier Mobility in Semiconductor Nanowires Based on the Spatially Dependent Boltzmann Transport Equation

Fuente: arXiv
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Main Authors: He, Zirui, Gao, Shang-Peng, Chen, Meng
Format: Preprint
Published: 2025
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author He, Zirui
Gao, Shang-Peng
Chen, Meng
author_facet He, Zirui
Gao, Shang-Peng
Chen, Meng
contents Carrier mobility in bulk semiconductors is typically governed by electron-phonon (e-ph) scattering. In nanostructures, spatial confinement can lead to significant surface scattering, lowering mobility and breaking the spatial homogeneity assumption of conventional models. In this work, a fully ab initio framework based on the spatially dependent Boltzmann transport equation for one-dimensional nanowires is developed. We apply it to Si and GaN assuming diffusive surface scattering, and reveal the mobility-diameter relation: $μ_\mathrm{1D} = μ_\mathrm{bulk} \left[1-\left(d/d_0\right)^{-β}\right]$. The parameter $d_0$, comparable to the carrier mean free path, defines a boundary layer exhibiting a considerable mobility gradient, and also quantifies the competition between e-ph and surface scattering together with $β$. We further discuss the effects of orientation, cross-sectional shape, and temperature. Moreover, experimental data are generally lower than our predictions, possibly due to structural imperfections, systematic errors from measurements, etc. Therefore, our theoretical method can provide an intrinsic benchmark toward optimized experimental realizations.
format Preprint
id arxiv_https___arxiv_org_abs_2511_02561
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle First-principles Prediction of Carrier Mobility in Semiconductor Nanowires Based on the Spatially Dependent Boltzmann Transport Equation
He, Zirui
Gao, Shang-Peng
Chen, Meng
Materials Science
Carrier mobility in bulk semiconductors is typically governed by electron-phonon (e-ph) scattering. In nanostructures, spatial confinement can lead to significant surface scattering, lowering mobility and breaking the spatial homogeneity assumption of conventional models. In this work, a fully ab initio framework based on the spatially dependent Boltzmann transport equation for one-dimensional nanowires is developed. We apply it to Si and GaN assuming diffusive surface scattering, and reveal the mobility-diameter relation: $μ_\mathrm{1D} = μ_\mathrm{bulk} \left[1-\left(d/d_0\right)^{-β}\right]$. The parameter $d_0$, comparable to the carrier mean free path, defines a boundary layer exhibiting a considerable mobility gradient, and also quantifies the competition between e-ph and surface scattering together with $β$. We further discuss the effects of orientation, cross-sectional shape, and temperature. Moreover, experimental data are generally lower than our predictions, possibly due to structural imperfections, systematic errors from measurements, etc. Therefore, our theoretical method can provide an intrinsic benchmark toward optimized experimental realizations.
title First-principles Prediction of Carrier Mobility in Semiconductor Nanowires Based on the Spatially Dependent Boltzmann Transport Equation
topic Materials Science
url https://arxiv.org/abs/2511.02561