Electronic and Thermoelectric Properties of Al doped Mg₂Si Material: DFT Study

详细信息    查看全文

• 作者：Kulwinder Kaur ; ^{kulwindercmp@gmail.com" class="auth_mail" title="E-mail the corresponding author} ; Ranjan Kumar ^{ranjan@pu.ac.in" class="auth_mail" title="E-mail the corresponding author}
• 关键词：Semiconductor ; Thermoelectric ; Density functional theory ; Seebeck coefficient ; Electronic properties
• 刊名：Materials Today: Proceedings
• 出版年：2016
• 出版时间：2016
• 年：2016
• 卷：3
• 期：6
• 页码：1785-1791
• 全文大小：1498 K

文摘

Magnesium Silicide and related alloys are very important for thermoelectric applications because of their non toxic nature, thermal stability, low density, relative abundance and low cost of production. In the present paper we have calculated electronic and thermoelectric properties of Al doped Mg₂Si material (Mg_2-xAl_xSi, x=0.125, 0.25, 0.375) using Pseudo potential plane wave method based on DFT and Semi classical Boltzmann theory. Mg₂Si semiconductor shows metallic nature when doped with Al atom and the conduction bands near Fermi level are composed of Si 3p, Mg 3s,3p and Al 3p. The calculations show ntype conduction, indicating that the electrical conduction is due to electron. The electrical conductivity increases with temperature; the negative value of Seebeck Coefficient also shows that the conduction is due to electron. The thermal conductivity increases slightly upon Al doping with increasing temperature due to the much larger contribution of lattice thermal conductivity over electronic thermal conductivity. In this paper we have calculated Seebeck coefficient, electrical conductivity and electronic contribution of thermal conductivity. The thermoelectric properties of doped system have been calculated in this temperature range 100K-1200K.