arXiv subjects

V. V. Nikolaev

Publications and source records attributed to V. V. Nikolaev.

4 recordsLinked to original sources

arXiv2016

Phenomenological theory of optical broadening in zero-dimensional systems applied to silicon nanocrystals

We develop a phenomenological theory of inhomogeneous broadening in zero-dimensional systems and apply it to study photoluminescence (PL) spectra of silicon nanocrystals measured at helium and room temperatures. The proposed approach allowed us to explain experimentally observed PL peak asymmetry, linear dependence of the peak width on its maximum and anomalous alteration of spectral characteristics with temperature increase.

cond-mat.mes-hall↗

arXiv2003

Excitonic Mott transition in double quantum wells

We consider an electron-hole system in double quantum wells theoretically. We demonstrate that there is a temperature interval over which an abrupt jump in the value of the ionization degree occurs with an increase of the carrier density or temperature. The opposite effect - the collapse of the ionized electron-hole plasma into an insulating exciton system - should occur at lower densities. In addition, we predict that under certain conditions there will be a sharp decrease of the ionization degree with increasing temperature - the anomalous Mott transition. We discuss how these effects could be observed experimentally.

cond-mat.stat-mech↗

arXiv2001

Photon recycling white light emitting diode based on InGaN multiple quantum well heterostructure

A numerical method based on the transfer matrix technique is developed to calculate the luminescence spectra of complex layered structures with photon recycling. Using this method we show a strong dependence of the emission spectra on the optical eigenmode structure of the device. The enhancement of the photon recycling and the LED external efficiency can be achieved by placing the active regions inside single or coupled microcavities.

cond-mat.mtrl-sci↗

arXiv2001

Statistical mechanics of screened spatially indirect excitons

We study thermodynamic properties of spatially separated electron-hole plasma in double-layered systems using Green function formalism. The screening of the Coulomb interaction is considered in the framework of Thomas-Fermi approximation, and a qualitatively new mechanism of screening by indirect excitons is taken into account. The exciton density is shown to decrease sharply with increasing electron-hole separation up to one exciton Born radius. The strong mutual enhancement of screening and charge-separation effects is found.

cond-mat.str-el↗