在无机/有机批量相复合材料中选择性电荷载体传输和双极导:优化低温热电性能
Cham Kim1, Taewook Kim2, Jaehun Cho1
1Division of Nanotechnology, Daegu Gyeongbuk Institute of Science and Technology (DGIST), 333 Techno Jungang-daero, Daegu 42988, Republic of Korea.
ACS applied materials & interfaces
|December 18, 2023
概括
本研究介绍了一种使用导电聚合物 (PEDOT:PSS) 和胺化物 (Bi2Te3) 进行增强低温热电应用的新型复合材料. 复合材料表现出更好的热电性能,使其成为能源采集技术的有希望的替代品.
科学领域:
- 材料科学 材料科学 材料科学
- 凝聚物质物理学 凝聚物质物理学
- 纳米技术纳米技术
背景情况:
- 导电性聚合物在热电应用中具有较低的导热率.
- 土化物 (Bi2Te3) 是一种关键的无机热电材料.
- 低温热电装置需要高效的材料.
研究的目的:
- 开发一种用于低温热电应用的新型散相复合材料.
- 通过加入导电聚合物来增强Bi2Te3的热电性能.
- 研究界面能量屏障和双极导电对热电特性的影响.
主要方法:
- 一种由无机热电矩阵 (Bi2Te3) 和导电聚合物填充物 (PEDOT:PSS) 组成的复合材料的制造.
- 复合材料的热电特性,包括Seebeck系数,功率因子和导热率的表征.
- 对载体运输机制的分析,重点关注能量过效应和双极传导.
主要成果:
- 由于能量过效应,复合材料与原始Bi2Te3相比显著提高了Seebeck系数.
- 观察到西贝克系数的明显温度依赖,归因于双极导电.
- 复合材料显示热导率大大降低,从而提高了热电性能.
- 在380K时达到1.26左右的最大功率 (ZT),在323-423K时达到1.23的平均ZT.
结论:
- 开发的Bi2Te3/PEDOT:PSS复合材料在低温应用中表现出优越的热电性能.
- 能量过效应和双极导电是提高性能的关键机制.
- 这种复合材料作为一个有前途的n型材料,补充p型Bi2Te3基合金.
相关概念视频
01:21Carrier Transport
449
The generation of electrical current in semiconductors is fundamentally driven by two mechanisms: drift and diffusion. These processes are essential for the functionality and performance of semiconductor-based devices.
Drift Current:
The drift of charge carriers is started by an external electric field (E). Charged particles, such as electrons and holes, experience an acceleration between collisions with lattice atoms. For electrons, this results in a drift velocity (vd) given by:
Drift Current:
The drift of charge carriers is started by an external electric field (E). Charged particles, such as electrons and holes, experience an acceleration between collisions with lattice atoms. For electrons, this results in a drift velocity (vd) given by:
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01:20Types of Semiconductors
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Intrinsic semiconductors are highly pure materials with no impurities. At absolute zero, these semiconductors behave as perfect insulators because all the valence electrons are bound, and the conduction band is empty, disallowing electrical conduction. The Fermi level is a concept used to describe the probability of occupancy of energy levels by electrons at thermal equilibrium. In intrinsic semiconductors, the Fermi level is positioned at the midpoint of the energy gap at absolute zero. When...
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01:22Semiconductors
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There is variation in the electrical conductivity of materials - metals, semiconductors, and insulators that are showcased with the help of the energy band diagrams.
Metals such as copper (Cu), zinc (Zn), or lead (Pb) have low resistivity and feature conduction bands that are either not fully occupied or overlap with the valence band, making a bandgap non-existent. This allows electrons in the highest energy levels of the valence band to easily transition to the conduction band upon gaining...
Metals such as copper (Cu), zinc (Zn), or lead (Pb) have low resistivity and feature conduction bands that are either not fully occupied or overlap with the valence band, making a bandgap non-existent. This allows electrons in the highest energy levels of the valence band to easily transition to the conduction band upon gaining...
708