WoS İndeksli Yayınlar Koleksiyonu
Permanent URI for this collectionhttps://hdl.handle.net/20.500.12573/394
Browse
2 results
Search Results
Article Citation - WoS: 9Citation - Scopus: 11The Intersubband Optical Properties of a Two-Electron Quantum Dot-Quantum Well Heterostructure(Academic Press Ltd- Elsevier Science Ltd, 2015-10) Aydin, Rasit; Tas, Hatice; Sahin, MehmetIn this paper, both linear and third-order nonlinear optical properties of two-electron in a semiconductor core/shell/well/shell quantum dot (QD) heterostructure for cases with and without a hydrogenic donor impurity have been investigated in a detailed manner as depending on the structure parameters. For this purpose, first, the energy eigenvalues and corresponding wave functions of the structure have been computed as a function of the layer thicknesses by means of the self-consistent solution of the Poisson and Schrodinger equations in envelope function effective mass approximation. Second, using these energy eigenvalues and their wave functions obtained from the calculations, both linear and third-order nonlinear optical properties of the multi-shell QD (MSQD) with two-electron have been determined as a function of the photon energies and shell thicknesses. Also, all procedures mentioned above have been repeated for negatively charged donor impurity (D-) located in the center of the same structure. Finally, obtained results have been presented comparatively for cases with and without the impurity. (C) 2015 Elsevier Ltd. All rights reserved.Article Citation - WoS: 26Citation - Scopus: 29A Detailed Investigation of Electronic and Optical Properties of the Exciton, the Biexciton and Charged Excitons in a Multi-Shell Quantum Dot Nanocrystal(IOP Publishing Ltd, 2014-06-19) Akturk, Abdurrahman; Sahin, Mehmet; Koc, Fatih; Erdinc, AhmetIn the present study, the electronic and optical properties of the exciton (X), the biexciton (XX) and charged excitons (X- and X+) in a multi-shell quantum dot nanocrystal have been systematically explored in detail. The electronic properties have been determined in the framework of the single-band effective mass approximation. For this purpose, the Poisson-Schrodinger equations have been solved self-consistently in the Hartree approximation. In the electronic structure calculations for XX, X- and X+, the quantum mechanical exchange-correlation potentials between particles of the same type have been taken into account in the local density approximation. Some optical parameters, such as the overlap integrals, recombination oscillator strengths, radiative lifetimes, etc, have been determined by using the single-particle energy levels and wavefunctions obtained. A different approximation, reported in Sahin and Koc 2013 Appl. Phys. Lett. 102 183103, has been used in the recombination oscillator strength calculations. The results have been presented comparatively as a function of the shell thicknesses, and the well widths and probable physical reasons underlying them have been discussed in detail.