Department of Energy Science, Sungkyunkwan University, Suwon 440-476 (Korea).
Center for Integrated Nanostructure Physics, Institute for Basic Science (IBS), Sungkyunkwan University, Suwon 440-476 (Korea).
ChemSusChem. 2015 Jul 20;8(14):2312-26. doi: 10.1002/cssc.201403485. Epub 2015 Mar 17.
Thermoelectrics, which transports heat for refrigeration or converts heat into electricity directly, is a key technology for renewable energy harvesting and solid-state refrigeration. Despite its importance, the widespread use of thermoelectric devices is constrained because of the low efficiency of thermoelectric bulk alloys. However, boundary engineering has been demonstrated as one of the most effective ways to enhance the thermoelectric performance of conventional thermoelectric materials such as Bi2 Te3 , PbTe, and SiGe alloys because their thermal and electronic transport properties can be manipulated separately by this approach. We review our recent progress on the enhancement of the thermoelectric figure of merit through boundary engineering together with the processing technologies for boundary engineering developed most recently using Bi2 Te3 -based bulk alloys. A brief discussion of the principles and current status of boundary-engineered bulk alloys for the enhancement of the thermoelectric figure of merit is presented. We focus mainly on (1) the reduction of the thermal conductivity by grain boundary engineering and (2) the reduction of thermal conductivity without deterioration of the electrical conductivity by phase boundary engineering. We also discuss the next potential approach using two boundary engineering strategies for a breakthrough in the area of bulk thermoelectric alloys.
热电材料可以直接将热能用于制冷或转换为电能，是可再生能源收集和固态制冷的关键技术。尽管其重要性不言而喻，但由于热电体合金的效率低下，热电设备的广泛应用受到了限制。然而，边界工程已被证明是提高传统热电材料（如 Bi2 Te3 、PbTe 和 SiGe 合金）热电性能的最有效方法之一，因为通过这种方法可以分别操纵其热和电子输运性能。我们综述了通过边界工程提高热电优值的最新进展，以及最近使用 Bi2 Te3 基块体合金开发的边界工程加工技术。简要讨论了通过边界工程提高热电优值的块体合金的原理和现状。我们主要集中在（1）通过晶界工程降低热导率，以及（2）通过相界工程降低热导率而不恶化电导率。我们还讨论了使用两种边界工程策略在突破块状热电合金领域的下一个潜在方法。
