Electronic and optical properties of single excitons and biexcitons in type-II quantum dot nanocrystals

Journal Article · Wed May 21 04:00:00 EDT 2014 · Journal of Applied Physics

DOI:https://doi.org/10.1063/1.4876323· OSTI ID:22275537

Koc, Fatih ^[1]; Sahin, Mehmet ^[1]

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1. Department of Physics, Faculty of Sciences, Selcuk University, 42075 Konya (Turkey)

In this study, a detailed investigation of the electronic and optical properties (i.e., binding energies, absorption wavelength, overlap of the electron-hole wave functions, recombination oscillator strength, etc.) of an exciton and a biexciton in CdTe/CdSe core/shell type-II quantum dot heterostructures has been carried out in the frame of the single band effective mass approximation. In order to determine the electronic properties, we have self-consistently solved the Poisson-Schrödinger equations in the Hartree approximation. We have considered all probable Coulomb interaction effects on both energy levels and also on the corresponding wave functions for both single exciton and biexciton. In addition, we have taken into account the quantum mechanical exchange-correlation effects in the local density approximation between same kinds of particles for biexciton. Also, we have examined the effect of the ligands and dielectric mismatch on the electronic and optical properties. We have used a different approximation proposed by Sahin and Koc [Appl. Phys. Lett. 102, 183103 (2013)] for the recombination oscillator strength of the biexciton for bound and unbound cases. The results obtained have been presented comparatively as a function of the shell thicknesses and probable physical reasons in behind of the results have been discussed in a detail.

• OSTI ID: 22275537
• Journal Information: Journal of Applied Physics, Journal Name: Journal of Applied Physics Journal Issue: 19 Vol. 115; ISSN JAPIAU; ISSN 0021-8979
• Country of Publication: United States
• Language: English

Related Subjects

75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
77 NANOSCIENCE AND NANOTECHNOLOGY
BINDING ENERGY
CADMIUM SELENIDES
CADMIUM TELLURIDES
CORRELATIONS
CRYSTALS
DIELECTRIC MATERIALS
ELECTRONIC STRUCTURE
ENERGY LEVELS
EXCITONS
HARTREE-FOCK METHOD
HETEROJUNCTIONS
HOLES
OPTICAL PROPERTIES
OSCILLATOR STRENGTHS
QUANTUM DOTS
QUANTUM MECHANICS
RECOMBINATION
SCHROEDINGER EQUATION
WAVE FUNCTIONS