Advanced thermoelectric properties in 1D quantum-confined core-shell nanowire heterostructures

该提议旨在建立核壳半导体纳米线异质结构作为先进纳米热电材料的实验平台，该材料利用量子限制介导的载流子传输和由核壳结构定制的声子性质的几个优点。基于申请人取得的第一个有希望的进展，该项目的重点是探索新型的基于III-V族的核-壳纳米线，这些纳米线同时提供高载流子迁移率，强一维约束与载流子的长准弹道平均自由路径，以及大的原子质量对比度和限制热传输的结构特征。特别注意将针对迄今未开发的InAs-AlAsSb核壳纳米线作为一种新的高迁移率晶格匹配的1D n沟道，其中的关键因素将管理1D运输进行评估，并在热功率相关的1D-子带结构突出增强。将进行相关的热输运光谱，以评估晶格热导率最小化通过调谐声子散射通过尺寸效应，合金化和多壳界面的核-壳结构。由于未来的功能性纳米热电器件需要n沟道和p沟道器件，我们还将把为n型InAs-AlAsSb沟道开发的方法应用于高迁移率p型GaSb-AlAsSb沟道。在高迁移率n-InAs和p-GaSb沟道上的联合努力将进一步为双极纳米热电器件以及Si基CMOS逻辑电路中的未来共集成方案奠定重要基础。

This proposal aims to establish core-shell semiconductor nanowire heterostructures as an experimental platform for advanced nano-thermoelectric materials that exploit several advantages of quantum confinement mediated carrier transport and phonon properties tailored by the core-shell structure. Based on first promising advances made by the applicant, the focus of this project is to explore new types of III-V based core-shell nanowires that simultaneously offer high carrier mobility, strong 1D-confinement with long quasi-ballistic mean free paths of carriers, as well as large atomic mass contrast and structural features that limit thermal transport. Particular attention will be directed towards hitherto unexplored InAs-AlAsSb core-shell nanowires as a new high-mobility lattice-matched 1D n-channel, where key factors governing 1D-transport will be evaluated and enhancements in thermopower related to the 1D-subband structure highlighted. Correlated thermal transport spectroscopy will be performed to evaluate the lattice thermal conductivity minimized by tuning phonon scattering via size effects, alloying and multi-shell interfaces in the core-shell structure. As future functional nano-thermoelectrics require both n- and p-channel devices, we will also apply the methodologies developed for n-type InAs-AlAsSb channels to high-mobility p-type GaSb-AlAsSb channels. The combined efforts on high-mobility n-InAs and p-GaSb channels will further lay important grounds for ambipolar nano-thermoelectrics as well as for future co-integration schemes in Si-based CMOS logic circuits.