Two types of isolated (quantum) emitters related to dislocations in crystalline CdZnTe

Abstract

Based on the measurements of spectra and polarization of low-temperature (5 K) microphotoluminescence, two types of isolated quantum emitters formed due to the dislocations in crystalline CdZnTe have been identified. For an emitter of the first type, the spectral position of zero-phonon emission line (ZPL) corresponds to the well-known dislocation luminescence of CdZnTe. In this case, position and intensity of ZPL demonstrate high stability over time. For an emitter of the second type, ZPL is located 30–50 meV above the usual dislocation luminescence and is subjected to giant fluctuations of spectral position (~ 10 meV) and intensity. For each of the two types of emitters, coupling with lattice is confirmed by the presence of phonon replicas associated with longitudinal optical phonons in CdZnTe. A noticeable degree of linear polarization in the plane containing 〈110〉 directions indicates the strongly anisotropic nature of the corresponding electronic states and confirms their connection with dislocations.