Nonstandard Features of the Interaction of Single Luminescent Centers Formed by Partial Dislocation Cores in CdTe and ZnSe with Longitudinal Optical Phonons

摘要

Low-temperature (5 K) microphotoluminescence has been measured in order to study individual luminescent centers formed by the cores of partial dislocations in a CdTe/Si film and a ZnSe quantum well. It has been shown that these centers are characterized by a noticeable interaction with longitudinal optical (LO) phonons, whose quasimomentum corresponds to the center of the Brillouin zone. At the same time, the relative intensities of LO- and 2LO-phonon replicas differ by an order of magnitude from the values predicted by the Huang-Rhys formula, which describes the intensities of multi-LO-phonon replicas for impurity luminescent centers. The nonstandard intensity distribution of phonon replicas is attributed to a change in the curvature of the adiabatic potential (frequency defect), which is due to the instability of the bond structure in the dislocation core with respect to the state of the electronic subsystem.