文章基本信息

标题：Enhanced Thermoelectric Efficiency of Porous Silicene Nanoribbons
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作者：Hatef Sadeghi ; Sara Sangtarash ; Colin J. Lambert 等
期刊名称：Scientific Reports
电子版ISSN：2045-2322
出版年度：2015
卷号：5
DOI：10.1038/srep09514
出版社：Springer Nature
摘要：There is a critical need to attain new sustainable materials for direct upgrade of waste heat to electrical energy via the thermoelectric effect. Here we demonstrate that the thermoelectric performance of silicene nanoribbons can be improved dramatically by introducing nanopores and tuning the Fermi energy. We predict that values of electronic thermoelectric figure of merit ZT_e up to 160 are achievable, provided the Fermi energy is located approximately 100 meV above the charge neutrality point. Including the effect of phonons yields a value for the full figure of merit of ZT = 3.5. Furthermore the sign of the thermopower S can be varied with achievable values as high as S = +/− 500 μV/K. As a method of tuning the Fermi energy, we analyse the effect of doping the silicene with either a strong electron donor (TTF) or a strong electron acceptor (TCNQ) and demonstrate that adsorbed layers of the former increases ZT_e to a value of 3.1, which is insensitive to temperature over the range 100 K – 400 K. This combination of a high, temperature-insensitive ZT_e , and the ability to choose the sign of the thermopower identifies nanoporous silicene as an ideal thermoelectric material with the potential for unprecedented performance.