First Principle Investigation of Structural, Electronic and Optical Properties of Quaternary BxInyGa1−x−yN Compounds

We report on our results obtained on the physical properties of BxInyGa[Formula: see text]N quaternary alloys in the zinc-blende phase that are thoroughly considered by the linearized augmented plane wave method, with a full potential within density functional theory, for different concentrations [Formula: see text] and [Formula: see text] as employed in the Wien2k code. We calculated the structural properties, including lattice constant [Formula: see text] and the bulk modulus [Formula: see text]. We computed as well the band structures, the dielectric constant and the refractive index of our quaternary alloys compounds. Finally, nonlinear dependence on the compositions [Formula: see text] and [Formula: see text] are investigated in-depth and still expecting for experimental confirmations. To the best of our knowledge, this is the first theoretical investigation of BxInyGa[Formula: see text]N alloy conducted to date.

The Effect of Sn Doping on the Thermoelectric Properties of SiGe Using First Principle Technique

The thermoelectric properties of hexagonal SiGe doped with Sn with doping percentage of 12.5% and 25% were investigated using linearised augmented plane wave method using the WIEN2k package and semiclassical Boltztmann Transport equation using the BoltzTraP software for the purpose of understanding the role of Sn as a dopant in the SiGe. For temperature range of 300 to 1000 K, it can be seen that by doping with Sn, there is an improvement in overall thermal conductivity of the samples with the highest improvement is in the 25% doped sample. The conductivity vs temperature for 25% Sn doped SiGe also shows higher value through temperature range from 300 K to 1000 K, however the Seebeck coefficient decreases with Sn doping percentage for the same temperature range. Due to lower Seebeck coefficient and higher thermal conductivity values, the overall thermoelectric coefficient, ZT, of the doped compound is lower than the SiGe values with highest ZT equal to 0.29 and 0.17 at 650 K for 12.5% and 25% respectively while the ZT of simulated SiGe at 650 K is 0.35. Thus 25% Sn doping actually reduce the ZT but enhanced the thermal and electrical conductivity of SiGe for temperature range of 300 to 1000 K.

Newly discovered Topological Insulator Sr3SnO for Spintronics, Optical and Electronic properties

A theoretical study of the electronic and optical properties of dilute magnetic semiconductor Sr3SnO is presented, using the full potential linearized augmented plane wave method. The Perdew Burke Ernzerhof (GGA08) (generalized gradient approximation) is used for the total energy calculations, while the Modified Becke–Johnson (MBJ) is used for electronic structure calculations since this functional was designed to reproduce as well as possible the exact exchange correlation potential rather than the total energy, and as a result gives significantly improved results such as band gap and electronic structure. In this study, we have investigated the optical properties by means of first-principles density-functional total-energy calculation using the all-electron full potential linear augmented plane-wave method (FPLAPW).