半导体中的格子动力学和热传输与抗结合价值带
Jiaoyue Yuan1,2, Yubi Chen1,2, Bolin Liao1
1Department of Mechanical Engineering, University of California, Santa Barbara, California 93106, USA.
Journal of the American Chemical Society
|August 11, 2023
概括
研究人员发现了一种新方法,通过分析抗结合价值带来发现超低导热率的材料. 这种方法确定了600多种稳定的半导体,为先进的热电材料铺平了道路.
科学领域:
- 材料科学
- 固态物理
- 凝聚物质物理学
背景情况:
- 高热电性能依赖于控制热导率和理解声子传输.
- 一个关键的挑战是在晶体固体中实现超低的晶格导热率.
- 识别具有本质低导热性的新材料对于技术进步至关重要.
研究的目的:
- 使用最高占值带的抗结合特性作为发现超低导热性的材料的描述符.
- 调查抗结合价值带 (ABVB) 和低晶格导热率之间的关系.
- 识别和分析具有超低导热性的新型半导体材料.
主要方法:
- 在模型系统 (PbTe,CsPbBr3) 中研究了ABVB和低晶格导热之间的联系.
- 在材料项目数据库中进行高通量搜索以寻找具有抗结合价值带的稳定二元半导体.
- 在确定XS家族 (X = K,Rb,Cs) 中对化学键和热传输进行了全面分析.
主要成果:
- 确定了600多个具有抗结合价值带特征的实验稳定的二元半导体.
- 在室温下,XS家族 (性金属K,Rb,Cs) 的热导率极低 (<1W/mK).
- 超低的热导率归因于由ABVB产生的弱化键和增加的声不和性.
结论:
- 占据最高的价值带的抗结合特性是发现超低导热性的材料的有效描述.
- 这些发现为晶体中的格子动力学和声子传输提供了化学洞察力.
- 这项工作提供了合理设计具有内在低晶格导热性的材料的实用方法.
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