Nonradiative carrier capture processes are very important for many electronic and optoelectronic devices. From the detrimental side, they decrease efficiencies of solar cells and light-emitting diodes, decrease lifetimes of minority carriers, etc. From the beneficial side they are very important for, e.g., electrically-driven single-photon emitters. The description of carrier capture by means of multiphonon emission has been evolving from 1950s up to 1990s, but the development stalled due to difficulties in describing the atomic and electronic structure of point defects. Only in 2012 did the first ab-initio description of carrier capture has been performed. Unfortunately, even those methodologies differ due to various approximations that have not been all tested. During this work a PhD student will be studying these approximations, such as the dependence of the final result on the number of phonons included in the description, and developing ab-initio methods further. It is expected that the project result in 3-4 high-quality publications (in journals like Phys. Rev. B or New J. Phys.), as well as a computer program that will be used by other researchers.
For more information, please contact the theme supervisor A. Alkauskas.