基于谷间光学声子驱动的锗锡谷间电子转移效应  

Electron transmission dynamics of Ge_(1–x )Sn_(x) alloys based on inter-valley electrons transferring effect

作　　者：黄诗浩 李佳鹏 李海林 卢旭星 孙钦钦 谢灯 HUANG Shihao;LI Jiapeng;LI Hailin;LU Xuxing;SUN Qinqin;XIE Deng(School of Electronic,Electrical Engineering and Physics,Fujian University of Technology,Fuzhou 350118,China)

机构地区：[1]福建理工大学电子电气与物理学院,福州350118

出　　处：《物理学报》2025年第3期150-156,共7页Acta Physica Sinica

基　　金：福建省自然科学基金(批准号:2022J01950)资助的课题。

摘　　要：谷间电子散射机制对锗锡材料的电子输运及光电性能的影响至关重要.本文构建了锗锡材料Γ和L能谷之间的谷间光学声子散射模型,研究其谷间电子转移效应.结果表明:散射率R_(ΓL)高于R_(LΓ)约一个数量级,同时RΓL随Sn组分的增加而减小,并在Sn组分大于0.1时趋于饱和;而R_(LΓ)几乎与Sn组分无关.谷间电子转移模型表明,Γ能谷电子填充率随Sn组分的增大呈现先增大后趋于饱和的规律,且与注入电子浓度关系不大.不考虑散射模型时,间接带Ge_(1–x)Sn_(x)材料Γ能谷电子填充率与注入电子浓度关系不大;直接带Ge_(1–x)Sn_(x)材料Γ能谷电子填充率与注入电子浓度相关,且电子浓度越低,Γ能谷电子填充率越大.研究成果有助于理解锗锡材料的电子迁移率、电输运和光电转换等微观机制,可为锗锡材料在微电子和光电子等领域提供理论参考价值.Ge_(1–x)Sn_(x) alloys have aroused great interest in silicon photonics because of their compatiblity with complementary metal-oxide-semiconductor(CMOS)technology.As a result,they are considered potential candidate materials.Owing to the significant differences in effective mass within the valleys,the unique dualvalley structure ofΓvalley and L valley in energy can improve the optoelectronic properties of Ge_(1–x)Sn_(x) alloys.Therefore,inter-valley scattering mechanisms between theΓand L valley in Ge_(1–x)Sn_(x) alloys are crucial for understanding the electronic transports and optical properties of Ge_(1–x)Sn_(x) materials.This work focuses on the theoretical analysis of inter-valley scattering mechanisms betweenΓand L valley,and hence on the electron transmission dynamics in Ge_(1–x)Sn_(x) alloys based on the phenomenological theory model.Firstly,the 30th-order k·p perturbation theory is introduced to reproduce the band structure of Ge_(1–x)Sn_(x).The results show that the effective mass of L valley is always about an order of magnitude higher than that ofΓvalley,which will significantly influence the electron distributions betweenΓand L valley.Secondly,the scattering mechanism is modeled in Ge_(1–x)Sn_(x) alloys.The results indicate that scattering rate R_(ΓL) is about an order of magnitude higher than RLΓ,while R_(ΓL) decreases with the increase of Sn composition and tends to saturate when Sn component is greater than 0.1.And RLΓis almost independent of the Sn component.Thirdly,kinetic processes of carriers betweenΓand L valley are proposed to analyze the electron transmission dynamics in Ge_(1–x)Sn_(x) alloys.Numerical results indicate that the electron population ratio forΓ-valley increases and then tends to saturation with the increase of Sn composition,and is independent of the injected electron concentration.The model without the scattering mechanism indicates that the electron population ratio forΓ-valley in indirect-Ge_(1–x)Sn_(x) alloys is independent of the injected ele

关 键 词：锗锡合金 电子-声子相互作用 散射模型 

分 类 号：O469[理学—凝聚态物理]