Publications by authors named "P A Mantashyan"

Liquid crystals (LC) are widely used in various optical devices due to their birefringence, dielectric anisotropy, and responsive behavior to external fields. Enhancing the properties of existing LCs through doping with nanoparticles, including semiconductor quantum dots, offers a promising route for improving their performance. Among various nanoparticles, QDs stand out for their high charge mobility, sensitivity in the near-infrared spectral region, and cost-effectiveness.

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Article Synopsis
  • Quantum dots (QDs) are known for their light-emitting properties, but there are still limitations in controlling their characteristics that affect higher-level applications.
  • This study focuses on engineering the exciton and biexciton emission order in indium phosphide (InP) QDs embedded in a polymer matrix using size, dielectric confinement, and electric fields.
  • Results suggest that smaller QDs (1 nm, 1.5 nm) in materials with high dielectric constants and external electric fields could enable optical gain and photon entanglement, providing a new approach beyond traditional type II core-shell QDs.
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The current work used the effective mass approximation conjoined with the finite element method to study the exciton states in a conical GaAs quantum dot. In particular, the dependence of the exciton energy on the geometrical parameters of a conical quantum dot has been studied. Once the one-particle eigenvalue equations have been solved, both for electrons and holes, the available information on energies and wave functions is used as input to calculate exciton energy and the effective band gap of the system.

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We have presented a theoretical investigation of exciton and biexciton states for the ground and excited levels in a strongly oblate ellipsoidal quantum dot made from GaAs. The variational trial wave functions for the ground and excited states of the exciton and biexciton are constructed on the base of one-particle wave functions. The energies for the ground and excited levels, depending on the ellipsoidal quantum dot's geometrical parameters, are depicted in the framework of the variational method.

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By using the numerical discretization method within the effective-mass approximation, we have theoretically investigated the exciton-related Raman scattering, interband absorption and photoluminescence in colloidal CdSe/CdS core/shell quantum dots ensemble. The interband optical absorption and photoluminescence spectra have been revealed for CdSe/CdS quantum dots, taking into account the size dispersion of the ensemble. Numerical calculation of the differential cross section has been presented for the exciton-related Stokes-Raman scattering in CdSe/CdS quantum dots ensemble with different mean sizes.

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