单层MoS₂中输运与气敏的多尺度系综蒙特卡洛方法
Multiscale ensemble Monte Carlo of transport and gas sensing in monolayer MoS$_2$
- Institute for Microelectronics, TU Wien（微电子研究所，维也纳工业大学）
机构由 AI 辅助整理，请以论文原文为准。
AI总结：
研究单层MoS₂输运与气敏问题，提出基于ViennaEMC求解器的自洽系综蒙特卡洛框架，经第一性原理验证，实现多尺度耦合，能再现器件传输特性及对多种气体的气敏响应。
AI中文摘要：
二维半导体如单层MoS₂，兼具实用带隙和全表面几何结构，在器件设计上有吸引力。本文提出基于ViennaEMC求解器的自洽系综蒙特卡洛（EMC）框架，含玻尔兹曼输运核及多种散射机制、简并自由载流子统计和自洽泊松耦合。内在输运参数经第一性原理密度泛函微扰理论验证。多尺度耦合中，EMC速度场特征为一维速度饱和通道模型提供输入，还扩展到环境/吸附质，再现了对氧气分压的电导率响应及对NO₂和NH₃气敏浓度依赖性。
英文摘要：
Two-dimensional semiconductors such as monolayer MoS2 combine a useful band gap with a thickness of three atomic planes, which places the entire carrier density within a few angstroms of the surface and makes them attractive both as transistor channels and as chemical sensors. We present a self-consistent ensemble Monte Carlo (EMC) framework for monolayer MoS2 built on the ViennaEMC solver, which couples a Boltzmann transport model to Poisson's equation with degenerate free-carrier statistics. The transport model carries wavevector-dependent acoustic, polar-optical, homopolar and intervalley phonon scattering within and between the K valleys and the spin-orbit-split Q valleys, together with remote substrate phonons, screened charged impurities and surface roughness. Every intrinsic input is computed from first principles for this work, the band structure of the K and Q valleys, the phonon energies, the sound velocities and the dielectric response, and the electron-phonon couplings from density-functional perturbation theory matrix elements at 34 explicit phonon wavevectors and from Wannier interpolation with the two-dimensional long-range treatment. The model therefore contains no fitted transport parameter and no coupling taken from another calculation, and its scattering rates are checked against an independent solution of the linearised Boltzmann equation with the same couplings. The EMC velocity-field characteristic feeds a one-dimensional channel model, verified against a direct self-consistent three-dimensional EMC simulation of the gated channel, which reproduces the measured transfer characteristics of a CVD monolayer device in air and vacuum. An ambient and adsorbate extension reproduces the measured conductivity response to oxygen partial pressure and the concentration dependence of NO2 and NH3 sensing of independent monolayer devices.
