Semiconducting properties of Mg2Ge single crystals

Optimization of the Electronic Band Structure and the Lattice Thermal Conductivity of Solid Solutions According to Simple Calculations: A Canonical Example of the Mg2Si1–x–yGexSny Ternary Solid Solution

“…All the compounds (Mg 2 Si, Mg 2 Ge, and Mg 2 Sn) share a similar electronic band structure consisting of two closely lying conduction bands (Figure and Table ). − However, while the bottom of the conduction band in Mg 2 Si and Mg 2 Ge is dominated by the light electron band (C L band) that has its origin in the 3p orbital of Mg hybridized with the s orbital and d-e g orbital of Si or Ge, the bottom of the conduction band of Mg 2 Sn is dominated by the heavy electron band (C H band) arising from hybridization between the 3s orbital of Mg and the d-t 2g orbital of Sn. − This implies that via the formation of solid solutions of Mg 2 Si 1– x Sn x and Mg 2 Ge 1– x Sn x , band convergence must take place at some particular value of x where the band edges of the light and heavy conduction bands attain comparable energy. When this happens, the band degeneracy ( N v ) of the system is increased, which leads to a significant enhancement of the density of states (DOS) effective mass m * = N v 2/3 m b * without increasing the band effective mass ( m b *).…”

Infrared absorption in magnesium germanide

“…This is in agreement with the results of Redin, who made estimates of from 0.03 eV to 0.0?? eV for donor ionization energies(40). However, if this were the case one would expect the primary peak to be much smaller at 4.2°K, when few electrons from the relatively deep level of 0.03 eV would be thermal ly excited to the conduction band.In short, there is no preponderance of evidencesupporting any of the possible mechanisms as giving rise to the absorption band in n-type MggGe.…”