Seminarium "Teoria i Modelowanie Nanostruktur"

In this presentation an entirely original and thorough first-principle study of the electronic properties of III-V-Bi alloys is presented. All III-V zinc-blende semiconductors alloyed with bismuth were studied, i.e. AlPBi, AlAsBi, AlSbBi, GaPBi, GaAsBi, GaSbBi, InPBi, InAsBi and InSbBi. State-of-the-art DFT methods were employed in order to calculate the electronic band structure of those materials in the whole Brillouin zone, and parameters describing the changes in the band structures were obtained and presented. The band structure calculations were followed by the investigation of defect properties in these systems. In this case, native as well as Bi-related defects in form of point or pair defects were studied in the low Bi composition (diluted regime). Hybrid functionals together with the Freysoldt correction scheme for charged defects were used in order to obtain the most accurate results of formation energies, binding energies and charge-state transition defect levels. In order to obtain the values for every studied defect, a regression model based on the obtained results was built, allowing for accurate prediction of the values without employing computationally expensive tools.The chemical trend for the materials were then discussed in terms of the applicability of the materials in optoelectronics.