中国物理B ›› 2016, Vol. 25 ›› Issue (5): 56401-056401.doi: 10.1088/1674-1056/25/5/056401

• CONDENSED MATTER: STRUCTURAL, MECHANICAL, AND THERMAL PROPERTIES • 上一篇    下一篇

Effect of pressure on electronic and thermoelectric properties of magnesium silicide: A density functional theory study

Kulwinder Kaur, Ranjan Kumar   

  1. Department of Physics, Panjab University, Chandigarh-160014, India
  • 收稿日期:2015-12-21 修回日期:2016-01-15 出版日期:2016-05-05 发布日期:2016-05-05
  • 通讯作者: Kulwinder Kaur E-mail:kulwinderphysics@gmail.com
  • 基金资助:
    Project supported by the Council of Scientific & Industrial Research (CSIR), India.

Effect of pressure on electronic and thermoelectric properties of magnesium silicide: A density functional theory study

Kulwinder Kaur, Ranjan Kumar   

  1. Department of Physics, Panjab University, Chandigarh-160014, India
  • Received:2015-12-21 Revised:2016-01-15 Online:2016-05-05 Published:2016-05-05
  • Contact: Kulwinder Kaur E-mail:kulwinderphysics@gmail.com
  • Supported by:
    Project supported by the Council of Scientific & Industrial Research (CSIR), India.

摘要: We study the effect of pressure on electronic and thermoelectric properties of Mg2}Si using the density functional theory and Boltzmann transport equations. The variation of lattice constant, band gap, bulk modulus with pressure is also analyzed. Further, the thermoelectric properties (Seebeck coefficient, electrical conductivity, electronic thermal conductivity) have been studied as a function of temperature and pressure up to 1200 K. The results show that Mg2Si is an n-type semiconductor with a band gap of 0.21 eV. The negative value of the Seebeck coefficient at all pressures indicates that the conduction is due to electrons. With the increase in pressure, the Seebeck coefficient decreases and electrical conductivity increases. It is also seen that, there is practically no effect of pressure on the electronic contribution of thermal conductivity. The paper describes the calculation of the lattice thermal conductivity and figure of merit of Mg2}Si at zero pressure. The maximum value of figure of merit is attained 1.83×10-3 at 1000 K. The obtained results are in good agreement with the available experimental and theoretical results.

关键词: semiconductors, effects of pressure, electric and thermal conductivity, density functional theory

Abstract: We study the effect of pressure on electronic and thermoelectric properties of Mg2}Si using the density functional theory and Boltzmann transport equations. The variation of lattice constant, band gap, bulk modulus with pressure is also analyzed. Further, the thermoelectric properties (Seebeck coefficient, electrical conductivity, electronic thermal conductivity) have been studied as a function of temperature and pressure up to 1200 K. The results show that Mg2Si is an n-type semiconductor with a band gap of 0.21 eV. The negative value of the Seebeck coefficient at all pressures indicates that the conduction is due to electrons. With the increase in pressure, the Seebeck coefficient decreases and electrical conductivity increases. It is also seen that, there is practically no effect of pressure on the electronic contribution of thermal conductivity. The paper describes the calculation of the lattice thermal conductivity and figure of merit of Mg2}Si at zero pressure. The maximum value of figure of merit is attained 1.83×10-3 at 1000 K. The obtained results are in good agreement with the available experimental and theoretical results.

Key words: semiconductors, effects of pressure, electric and thermal conductivity, density functional theory

中图分类号:  (Semiconductors)

  • 64.70.kg
74.62.Fj (Effects of pressure) 74.25.fc (Electric and thermal conductivity) 71.15.Mb (Density functional theory, local density approximation, gradient and other corrections)