Investigation of structural, elastic, and lattice-dynamical properties of Ca2Si, Ca2Ge, and Ca2Sn based on first-principles density functional theory

Exploiting the fraternal twin nature of thermoelectrics and topological insulators in Zintl phases as a tool for engineering new efficient thermoelectric generators

“…The Sr 2 X (X = Pb, Sn) and Ba 2 X (X = Si, Ge) phases We begin our discussion with the binary Sr 2 X (X = Pb, Sn) and Ba 2 X (X = Si, Ge) semiconducting Zintl phases. The Zintl AE 2 X (AE = Mg, Ca, Sr, Ba; X = Si, Ge, Sn, Pb) Zintl phases [153][154][155][156][157][158][159][160][161][162][163][164][165][166][167] are reported to crystallize in a orthorhombic TiNiSi-type structure with the space group Pnma (No. 62).…”

Improving the magnetic moment of Ca2Ge and promoting the conversion of semiconductors to diluted magnetic semiconductors using Mn-doping

“…20,21 The band structure and photoelectric characteristics of Ca 2 Ge have been studied using the rst principles method. 22 It is found that cubic phase Ca 2 Ge is a direct band-gap semiconductor with a band gap of 0.56 eV, and the lattice constant is 0.719 nm. 23 The stability of Ca-Ge alloys is affected by pressure and temperature, while the vibrational free energy depends only on temperature.…”

The Effect on the Electric Structure and Optical Properties of Ca<sub>2</sub>Ge Bulk with Sr-Doping

“…However, Ca 2 Ge is a direct semiconductor, has a simple orthorhombic structure and a cubic structure (The orthorhombic structure, which is a stable phase with an energy band gap of is 0.26 eV) [1] [2] [3] [4] [5]. Ca 2 Ge has attracted much attention for its potential to create new classes of environmentally conscious elec-tronics [6]. Recently, the study of Ca 2 Ge has a definite progress while is started relativity late, so the related literature reports and data available for reference.…”

“…In 2010, Yang used the first-principles method based on the density functional theory to study the electric structure of Ca 2 Ge, the results showed that Ca 2 Ge was a direct band gap semiconductor material with the band gap of 0.265 eV [4]. In 2015, Jun used the first-principles method base on the density functional theory to study the photon correlation spectroscopy of Ca 2 Ge, the results showed that the photon frequency of Ca 2 Ge was lower than Ca 2 Si in the low energy region; the results provide reference for the photoelectric properties of Ca 2 Ge in the next phase study [6]. The dielectric function is described the polarization response of the material under the condition of the electric field, it as a bridge establish the connection between microscopic photon excitation, electronic transmission associate and macroscopic visible optical properties, revealing the macroscopic dielectric properties of the micro mechanism.…”