You are cordially invited to the SCL online seminar of the Center for the Study of Complex Systems, which will be held on Thursday, 25 February 2021 at 14:00 on Zoom. The talk entitled

Pieces of physics behind electron mobility in materials: the case of II-VI semiconductors

will be given by Dr. Nenad Vukmirović (Scientific Computing Laboratory, Center for the Study of Complex Systems, Institute of Physics Belgrade). Abstract of the talk:

Electronic components based on semiconducting materials are present in our everyday life in a variety of devices. The main physical process that takes place in these devices is electronic transport through the material which is quantified by the electron mobility. Despite a tremendous progress in prediction of material properties from the crystal structure, it is still quite difficult to reliably calculate the electron mobility in a semiconducting material.

In this talk, the methodology for obtaining the electronic states, the phonon modes and the electron-phonon coupling constants within density functional theory will first be reviewed. Particular focus will be given on physical considerations necessary to perform accurate interpolation of electron-phonon coupling constants to a dense momentum grid in the first Brillouin zone. Modifications of the methodology necessary to correct for known shortcomings of local approximations in density functional theory will then be introduced. Our numerical implementation of the whole procedure for calculation of mobility from electron-phonon coupling constants will be briefly presented. Next, the results for temperature dependence of mobility in ZnSe, CdTe, ZnTe and CdSe will be shown and compared to experimental results from the literature. Finally, two simpler models which can be used to calculate the mobility will be introduced and their range of validity will be discussed.

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