Magnetic Field‐Enhanced Thermoelectric Performance in Dirac Semimetal Cd3As2 Crystals with Different Carrier Concentrations. (15th July 2019)

• Record Type: Journal Article
• Authors: Wang, Honghui; Luo, Xigang; Peng, Kunling; Sun, Zeliang; Shi, Mengzhu; Ma, Donghui; Wang, Naizhou; Wu, Tao; Ying, Jianjun; Wang, Zhengfei; Chen, Xianhui
• Is Part Of: Advanced functional materials. Volume 29:Number 37(2019)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2019-07-15
• Subjects: Cd3As2 -- magneto‐thermoelectric effects -- thermoelectrics -- topological materials; Materials -- Periodicals; Chemical vapor deposition -- Periodicals; 620.11
• DOI: 10.1002/adfm.201902437
• Languages: English
• ISSNs: 1616-301X

Abstract

Abstract: The magneto‐thermoelectric figure of merit ( ZT ) in crystals of the topological Dirac semimetal Cd3 As2 with different carrier concentrations is studied. The ZT s for all the crystals increase with the temperature and show maxima at high temperatures. Meanwhile, the temperatures corresponding to the ZT maxima increase with the carrier concentration. The limit to the improvement in ZT ( T ) at high temperature could be related to the unusual large enhancement in thermal conductivity at elevated temperatures. The bipolar effect and Dirac liquid behavior are presented as processes possibly responsible for the peculiar behavior of the thermal conductivity. Applying a transverse magnetic field initially leads to a dramatic enhancement and, subsequently, to a slight reduction in ZT for all the crystals. The maximum ZT achieved in a magnetic field increases with the carrier concentration and reaches 1.24 at 450 K in a magnetic field of 9 T for the crystal with the highest carrier concentration. It is expected that this work will be beneficial to the current interests in optimizing the thermoelectric properties of quantum topological materials. Abstract : A huge magneto‐thermoelectric figure of merit ( ZT ) in the topological Dirac semimetal Cd3 As2 is detected upon different levels of carrier concentrations. This is realized due to the combination of the dramatic enhancement of the Seebeck coefficient and the great reduction of the Lorenz number under magnetic field. ZT reaches 1.24 at 450 K in the crystal with the highest carrier density.