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Author Pandey, T.; Peeters, F.M.; Milošević, M.V. doi  openurl
  Title High thermoelectric figure of merit in p-type Mg₃Si₂Te₆: role of multi-valley bands and high anharmonicity Type A1 Journal article
  Year (down) 2023 Publication Journal of materials chemistry C : materials for optical and electronic devices Abbreviated Journal  
  Volume 11 Issue 33 Pages 11185-11194  
  Keywords A1 Journal article; Condensed Matter Theory (CMT)  
  Abstract Silicon-based materials are attractive for thermoelectric applications due to their thermal stability, chemical inertness, and natural abundance of silicon. Here, using a combination of first-principles and Boltzmann transport calculations we report the thermoelectric properties of the recently synthesized compound Mg3Si2Te6. Our analysis reveals that Mg3Si2Te6 is a direct bandgap semiconductor with a bandgap of 1.6 eV. The combination of heavy and light valence bands, along with a high valley degeneracy, results in a large power factor under p-type doping. We also find that Mg is weakly bonded both within and between the layers, leading to low phonon group velocities. The vibrations of the Mg atoms are localized and make a significant contribution to phonon-phonon scattering. This high anharmonicity, coupled with low phonon group velocity, results in a low lattice thermal conductivity of & kappa;(l) = 0.5 W m(-1) K-1 at room temperature, along the cross-plane direction. Combining excellent electronic transport properties and low & kappa;(l), p-type Mg3Si2Te6 achieves figure-of-merit (zT) values greater than 1 at temperatures above 600 K. Specifically, a zT of 2.0 is found at 900 K along the cross-plane direction. Our findings highlight the importance of structural complexity and chemical bonding in electronic and phonon transport, providing guiding insights for further design of Si-based thermoelectrics.  
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  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 001041124900001 Publication Date 2023-07-26  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 2050-7526; 2050-7534 ISBN Additional Links UA library record; WoS full record  
  Impact Factor 6.4 Times cited 1 Open Access Not_Open_Access  
  Notes Approved Most recent IF: 6.4; 2023 IF: 5.256  
  Call Number UA @ admin @ c:irua:198296 Serial 8821  
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