基于高取向纳米结构设计的热电材料及其器件集成

The rapid development of powerless sensor and high heat-flux electronic equipment require high performance thermoelectric device as cooler or power generator. However, because of their low efficiency, current thermoelectric materials have found limited commercial application. How to introduce nanotechnology into thermoelectric materials to achieve ZT breakthroughs has been the focus of research. At present, further improvement of thermoelectric materials and devices based on nanostructure has met bottlenecks. Due to the difficulty in coordinately regulating the electron -phonon transport in thermoelectric materials, new ideas are needed in order to further optimize the phonon and electron transport in thermoelectric devices. The key to solve these issues lies in the maintenance of structural stability of nanocrystal surface and heterogeneous interface in the service environment, which help to scatter phonon more efficiently and maintain smooth transport for electron carriers. .Therefore, here we propose to investigate the problem in coordinately regulating the electron -phonon transport in thermoelectric materials and devices by constructing highly oriented nanostructured materials. The project focuses on the design and fabrication of special nanostructure, microstructure evolution under the multi-field coupling, electron and phonon transport mechanism and preparation technology of electrode and device integration of bismuth telluride based thermoelectric materials, aiming at the fabrication of rapid cooling thermal control device under high heat flux and passive wireless sensor demonstration system based on ambient temperature gradient power generation. The proposed investigation is aimed at exploring the intrinsic relationship between materials composition, nanostructure, orientation and thermoelectric performances. The study will provide new knowledge, new technology and new material for future application of nanostructured thermoelectric materials and devices.

热电材料常用于制备微型电源或电子芯片制冷器件。如何利用纳米技术实现热电材料ZT值的突破一直是研究的重点。当前基于纳米结构的热电材料与器件性能的进一步提升面临瓶颈，热电材料体系内电子声子输运协同调控困难，器件对传热与导电的优化需要新思路。关键在于纳米晶面、异质界面在服役环境下能够保持结构稳定，实现对声子的有效散射并维持载流子通畅输运。本项目拟通过材料体系的高取向纳米结构构筑，解决材料与器件面临的电、热输运协同调控困难。系统研究碲化铋系热电材料特殊纳米结构设计与制备、多场耦合作用下的微观组织结构演化规律、电声输运机制、电极及器件集成制备技术，研制出高热流密度快速散热制冷热控装置和基于环境温差发电的无源无线传感器演示系统。建立材料组成、纳米结构、取向度及其热电性质的内在关系，为热电纳米材料及高效器件的未来应用提供原理、材料和系统等方面的基础支撑。

热电材料常用于制备微型电源或电子芯片制冷器件，利用纳米技术提升材料的热电性能一直是研究的重点，当前基于纳米结构的热电材料与器件性能的进一步提升面临瓶颈，热电材料体系内电子声子输运协同调控困难，器件对传热与导电的优化需要新思路。面向信息电子领域热电转换器件应用需求，本项目以Bi2Te3基热电材料为研究对象，系统研究了碲化铋系热电材料特殊纳米结构设计制备、多场耦合作用下的微观组织结构演化规律、电声输运机制、电极及器件集成制备技术，通过材料体系的高取向纳米结构构筑，解决材料与器件面临的电、热输运协同调控困难，获得高性能Bi2Te3基热电材料与器件；揭示了Bi2Te3基热电材料中成分、纳米结构、界面、晶粒取向和点缺陷对禁带宽度、载流子浓度和声子散射的作用机制和调控原理，建立服役环境下热电材料的组成、纳米结构形态及其热电性质的内在关系，研制出利用环境温差发电的无源无线传感以及用于发热组件快速主动散热的原理演示系统，为热电纳米材料及高效器件的应用提供原理、材料和系统等方面的基础支撑。