2019/03/12 by Naomi Hirayama, Tsutomu Iida, Mariko Sakamoto +2 · 1 citation
Physics and Astronomy · Materials Science · Chemistry · #Superconductivity in MgB2 and Alloys #Semiconductor materials and interfaces #Iron-based superconductors research #Electronegativity #Doping #Materials science #Thermoelectric effect #Impurity #Dopant #Interstitial defect #Condensed matter physics #Boron #Electrical resistivity and conductivity #Semiconductor #Silicide #Thermoelectric materials #Silicon #Chemistry #Thermodynamics #Metallurgy #Physics #Optoelectronics
paper · pdf · doi:10.1080/14686996.2019.1580537
openalex publication_date 2019/03/12 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/29
The narrow-gap magnesium silicide semiconductor Mg2Si is a promising mid-temperature (600–900 K) thermoelectric material. It intrinsically possesses n-type conductivity, and n-type dopants are generally used for improving its thermoelectric performance; however, the synthesis of p-type Mg2Si is relatively difficult. In this work, the hole doping of Mg2Si with various impurity atoms is investigated by performing first principles calculations. It is found that the Ag-doped systems exhibit comparable formation energies ΔE calculated for different impurity sites (Mg, Si, and interstitial 4b ones), which may explain the experimental instability of their p-type conductivity. A similar phenomenon is observed for the systems incorporating alkali metals (Li, Na, and K) since their ΔE values determined for Mg (p-type) and 4b (n-type) sites are very close. Among boron group elements (Ga and B), Ga is found to be favorable for hole doping because it exhibits relatively small ΔE values for Si (p-type) sites. Furthermore, the interstitial insertion of Cl and F atoms into the crystal lattice leads to hole doping because of their high electronegativity.