气候变化领域集成服务门户(CCPortal): Deep defect level engineering: A strategy of optimizing the carrier concentration for high thermoelectric performance

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DOI	10.1039/c8ee00112j
	Deep defect level engineering: A strategy of optimizing the carrier concentration for high thermoelectric performance
	Zhang Q.; Song Q.; Wang X.; Sun J.; Zhu Q.; Dahal K.; Lin X.; Cao F.; Zhou J.; Chen S.; Chen G.; Mao J.; Ren Z.
发表日期	2018
ISSN	17545692
起始页码	933
结束页码	940
卷号	11 期号:4
英文摘要	Thermoelectric properties are heavily dependent on the carrier concentration, and therefore the optimization of carrier concentration plays a central role in achieving high thermoelectric performance. The optimized carrier concentration is highly temperature-dependent and could even possibly vary within one order of magnitude in the temperature range of several hundreds of Kelvin. Practically, however, the traditional doping strategy will only lead to a constant carrier concentration, and thus the thermoelectric performance is only optimized within a limited temperature range. Here, we demonstrate that a temperature-dependent carrier concentration can be realized by simultaneously introducing shallow and deep defect levels. In this work, iodine (I) and indium (In) are co-doped in PbTe, where iodine acts as the shallow donor level that supplies sufficient electrons and indium builds up the localized half-filled deep defect state in the band gap. The indium deep defect state traps electrons at a lower temperature and the trapped electrons will be thermally activated back to the conduction band when the temperature rises. In this way, the carrier concentration can be engineered as temperature-dependent, which matches the theoretically predicted optimized carrier concentration over the whole temperature range. As a result, a room temperature ZT of ∼0.4 and a peak ZT of ∼1.4 at 773 K were obtained in the n-type In/I co-doped PbTe, leading to a record-high average ZT of ∼1.04 in the temperature range of 300 to 773 K. Importantly, since deep defect levels also exist in other materials, the strategy of deep defect level engineering should be widely applicable to a variety of materials for enhancing the thermoelectric performance across a broad temperature range. © 2018 The Royal Society of Chemistry.
英文关键词	Defects; Energy gap; High temperature engineering; Indium; IV-VI semiconductors; Thermoelectricity; Broad temperature ranges; Doping strategies; Lower temperatures; Temperature dependent; Temperature range; Thermally activated; Thermoelectric performance; Thermoelectric properties; Carrier concentration; concentration (composition); electrical property; electron; high temperature; indium; iodine; low temperature; optimization; performance assessment
语种	英语
来源期刊	Energy & Environmental Science
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/190261
作者单位	Department of Materials Science and Engineering, Harbin Institute of Technology, Shenzhen Guangdong, 518055, China; Department of Mechanical Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, United States; Department of Physics and TcSUH, University of Houston, Houston, TX 77204, United States; School of Science, Harbin Institute of Technology, Shenzhen Guangdong, 518055, China
推荐引用方式 GB/T 7714	Zhang Q.,Song Q.,Wang X.,et al. Deep defect level engineering: A strategy of optimizing the carrier concentration for high thermoelectric performance[J],2018,11(4).
APA	Zhang Q..,Song Q..,Wang X..,Sun J..,Zhu Q..,...&Ren Z..(2018).Deep defect level engineering: A strategy of optimizing the carrier concentration for high thermoelectric performance.Energy & Environmental Science,11(4).
MLA	Zhang Q.,et al."Deep defect level engineering: A strategy of optimizing the carrier concentration for high thermoelectric performance".Energy & Environmental Science 11.4(2018).