Charge transport in crystals at finite-temperature

Wednesday, March 28, 2018 - 2:00pm - 3:00pm
Lind 409
Emil Prodan (Yeshiva University)
Most electronic devices operate at room temperature and above. At such temperatures, the atoms undergo a vigorous thermal motion which can affect the transport coefficients of a material in qualitative and quantitative ways. First, the electrons navigate in a disordered environment, which can Anderson localize parts of the energy spectrum. The mobility edges, which separate the extended and localized spectral regions and determine the activated behavior of the transport coefficients of a semi-conductor, are known to be highly dependent on the strength and character of the disordered potentials, hence thermal disorder can induce large effects. Secondly, the phonons can be Anderson localized, hence drastically affecting the dissipation mechanisms.

In this talk, I will discuss our recent effort on quantifying the thermal disorder in semiconductors using first principle quantum molecular dynamics and present an explicit analysis of the pure Si crystal in the temperature range 300-1500K. In the second part I will present model simulations of disordered systems with an emphasis on the behavior of transport coefficients near a localization/delocalization transition. This work is in collaboration with Thomas Kuhne.