  The rapid development of optical technologies and applications revealed the
critical role of point defects affecting device performance. One of the
powerful tools to study influence of defects on charge capture and
recombination processes is thermoluminescence. The popular models behind
thermoluminescence and carrier capture processes are semi-classic though. They
offer good qualitative description, but implicitly exclude quantum nature of
the accompanying parameters, such as frequency factors and capture cross
sections. As a consequence, results obtained for a specific host material
cannot be successfully extrapolated to other materials. Thus, the main purpose
of our work is to introduce a reliable analytical model that describes
non-radiative capture and release of electrons from/to the conduction band
(CB). The proposed model is governed by Bose-Einstein statistics (for phonon
occupation) and Fermi's golden rule (for resonant charge transfer between the
trap and the CB). The constructed model offers a physical interpretation of the
capture coefficients and frequency factors, and seamlessly includes the Coulomb
neutral/attractive nature of traps. It connects the frequency factor to the
overlap of wavefunctions of the delocalized CB and trap states, and suggests a
strong dependence on the density of charge distribution, i.e. the
ionicity/covalency of the chemical bonds within the host. Separation of the
resonance condition from the accumulation/dissipation of phonons on the site
leads to the conclusion that the capture cross-section does not necessarily
depend on the trap depth. The model is verified by comparison to reported
experimental data, showing good agreement. As such, the model generates
reliable information about trap states whose exact nature is not completely
understood and allows to do materials research in a more systematic way.
