高性能GeTe热电器在面阶段和立方阶段
Juan Li1, Xinyue Zhang1, Xiao Wang1
1Interdisciplinary Materials Research Center, School of Materials Science and Engineering , Tongji University , Shanghai 201804 , China.
Journal of the American Chemical Society
|October 27, 2018
概括
在 Telluride (GeTe) 中的抗兴奋剂通过增强带退化和降低导热性来优化热电性能. 这项研究在立方体和方体面的GeTe阶段实现了高的热电功率 (zT) 超过2.
科学领域:
- 材料科学
- 固态物理
- 热电材料
背景情况:
- Telluride (GeTe) 在立方体和方体结构之间呈现相位过渡.
- 立方GeTe和相关的IV-VI半导体具有双价值带结构 (L和S带),由于高频段退化,对热电性能有利.
- 罗姆体GeTe显示了变化的带排序和分裂,为操纵带退化提供了新的途径.
研究的目的:
- 优化载体度,并使用 (Sb) 合物操纵GeTe的晶格扭曲.
- 为了最大限度地提高带退化和增强基于GeTe的热电的电子性能.
- 通过Sb-doping诱导的声子散射来降低格子的导热性.
主要方法:
- Telluride (GeTe) 的抗 (Sb) 兴奋剂.
- 对载体度和状格子扭曲的研究.
- 对波段结构操纵和声子散射机制的分析.
主要成果:
- Sb-doping成功优化了载体度,并控制了状晶格的扭曲.
- Sb-doping 增强了带变性和促进了 PbTe 溶解性,从而增加了 Ge/Pb 替代缺陷的语子散射.
- 在低于800K的温度下,在面和立方GeTe相中都获得了超过2的优异热电值 (zT).
结论:
- 含有Sb的GeTe合金表现出优异的热电特性,使其成为800K以下应用的首选.
- 这项研究强调了操纵晶体结构对称性在推进热电材料中的关键作用.
- 这项工作为设计高性能热电器提供了途径,通过受控的注和结构修改.
相关概念视频
02:39Phase Diagrams
50.2K
A phase diagram combines plots of pressure versus temperature for the liquid-gas, solid-liquid, and solid-gas phase-transition equilibria of a substance. These diagrams indicate the physical states that exist under specific conditions of pressure and temperature and also provide the pressure dependence of the phase-transition temperatures (melting points, sublimation points, boiling points). Regions or areas labeled solid, liquid, and gas represent single phases, while lines or curves represent...
50.2K
02:31Phase Transitions
23.2K
Whether solid, liquid, or gas, a substance's state depends on the order and arrangement of its particles (atoms, molecules, or ions). Particles in the solid pack closely together, generally in a pattern. The particles vibrate about their fixed positions but do not move or squeeze past their neighbors. In liquids, although the particles are closely spaced, they are randomly arranged. The position of the particles are not fixed—that is, they are free to move past their neighbors to...
23.2K
01:28Inductance: Single-Phase And Three-Phase Line
628
Understanding the inductance of transmission lines is crucial for efficient design and operation in electrical power systems. This discussion delves into the inductance characteristics of single-phase two-wire and three-phase three-wire transmission lines with equal phase spacing.
Single-Phase Two-Wire Line:
A single-phase line consists of two solid cylindrical conductors, denoted as x and y. Each conductor carries phasor currents ix and iy, respectively. Given that the sum of these currents is...
Single-Phase Two-Wire Line:
A single-phase line consists of two solid cylindrical conductors, denoted as x and y. Each conductor carries phasor currents ix and iy, respectively. Given that the sum of these currents is...
628
01:25Capacitance: Single-Phase And Three-Phase Line
607
In electrical power systems, understanding the capacitance of transmission lines is fundamental for efficient operation.
Single-Phase Lines
Consider a single-phase, two-wire transmission line with equal phase spacing energized by a voltage source. One conductor carries a uniform positive charge, while the other carries an equal negative charge. The capacitance C of the line can be derived from the voltage V between the conductors. For a one-meter section of the line, the capacitance is given...
Single-Phase Lines
Consider a single-phase, two-wire transmission line with equal phase spacing energized by a voltage source. One conductor carries a uniform positive charge, while the other carries an equal negative charge. The capacitance C of the line can be derived from the voltage V between the conductors. For a one-meter section of the line, the capacitance is given...
607
01:19Phase Changes
5.4K
Phase transitions play an important theoretical and practical role in the study of heat flow. In melting or fusion, a solid turns into a liquid; the opposite process is freezing. In evaporation, a liquid turns into a gas; the opposite process is condensation.
A substance melts or freezes at a temperature called its melting point and boils or condenses at its boiling point. These temperatures depend on pressure. High pressure favors the denser form of the substance, so typically, high pressure...
A substance melts or freezes at a temperature called its melting point and boils or condenses at its boiling point. These temperatures depend on pressure. High pressure favors the denser form of the substance, so typically, high pressure...
5.4K
01:22Phase-lead and Phase-lag Controllers
550
Understanding the working function of different types of controllers can be illustrated with practical analogies, such as adjusting a stereo's volume equalizer. Cranking up the bass involves a phase-lead controller, which functions as a high-pass filter, while increasing the treble uses a phase-lag controller, which acts as a low-pass filter. PD controllers, similar to high-pass filters, enhance the system's response to high-frequency components. PI controllers, akin to low-pass...
550