arXiv subjects

Andrei V. Naumov

Publications and source records attributed to Andrei V. Naumov.

3 recordsLinked to original sources

arXiv2025

Model of luminescence and delayed luminescence correlated blinking in single CsPbBr$_3$ nanocrystals

Cesium lead halide nanocrystals and quantum dots are prominent materials for different types of applications because of their remarkable photophysical properties. However, they are also known to exhibit the same effects observed for non-perovskite colloidal semiconductor quantum dots such as blinking, photobleaching, delayed luminescence, etc. In this study we reveal the correlations between fast and delayed emission components for both the intensity and characteristic decay time for single CsPbBr$_3$ nanocrystals. In order to explain the phenomena observed, we propose a novel model of single CsPbBr$_3$ nanocrystals luminescence blinking based on the hypothesis of slow variations in the electron-phonon coupling.

cond-mat.mtrl-sci↗

arXiv2020

Low temperature spectral dynamics of single molecules in ultrathin polymer films

We studied the spectral dynamics of single fluorescent dye molecules embedded in ultrathin films (5 - 100 nm) of the amorphous polymer polyisobutylene at cryogenic temperatures and its variation with film thickness. Noticeable portion of molecules in the ensemble show a behavior which is inconsistent with the standard tunneling model: Their spectral lines are subject to irreversible spectral jumps, continuous shifting, and abrupt chaotic changes of the linewidth or jumping rate. In films thinner than 100 nm, the occurrence of "non-standard" spectral behavior increases with decreasing sample thickness at fixed excitation intensity. In addition, it also increases with laser intensity.

cond-mat.dis-nn↗

arXiv2019

Contribution of electron-phonon coupling to the luminescence spectra of single colloidal quantum dots

Luminescence spectroscopy experiments were realized for single colloidal quantum dots CdSe/ZnS in a broad temperature range above room temperature in a nitrogen atmosphere. Broadening and shifts of spectra due to the temperature change as well as due to spectral diffusion processes were detected and analyzed. A linear correlation between the positions of maxima and the squared linewidths of the spectra was found. This dependence was explained by a model which takes into account the slow variation of the electron-phonon coupling strength.

cond-mat.mes-hall↗