makale9_JAP_2009_HVD - Self-consistent computation of...

Info iconThis preview shows pages 1–2. Sign up to view the full content.

View Full Document Right Arrow Icon

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: Self-consistent computation of electronic and optical properties of a single exciton in a spherical quantum dot via matrix diagonalization method Mehmet Ş ahin, 1, a ! Sedat Nizamoglu, 2 A. Emre Kavruk, 3 and Hilmi Volkan Demir 4 1 Department of Physics, Faculty of Sciences, Selçuk University, Kampüs 42075 Konya, Turkey and Institute of Material Science and Nanotechnology, Bilkent University, 06800 Ankara, Turkey 2 Nanotechnology Research Center and Institute of Materials Science and Nanotechnology, Bilkent University, 06800 Ankara, Turkey and Department of Electrical and Electronics Engineering, Bilkent University, 06800 Ankara, Turkey 3 Department of Physics, Faculty of Sciences, Selçuk University, Kampüs 42075 Konya, Turkey 4 Nanotechnology Research Center and Institute of Materials Science and Nanotechnology, Bilkent University, 06800 Ankara, Turkey; Department of Electrical and Electronics Engineering, Bilkent University, 06800 Ankara, Turkey; and Department of Physics, Bilkent University, 06800 Ankara, Turkey s Received 14 April 2009; accepted 15 June 2009; published online 21 August 2009 d In this study, we develop and demonstrate an efficient self-consistent calculation schema that computes the electronic structure and optical properties of a single exciton in a spherical quantum dot s QD d with an interacting pair of electron and hole wave functions. To observe modifications on bands, wave functions, and energies due to the attractive Coulomb potential, the full numeric matrix diagonalization technique is employed to determine sublevel energy eigenvalues and their wave functions in effective mass approximation. This treatment allows to observe that the conduction and valance band edges bend, that the electron and hole wave functions strongly localize in the QD, and that the excitonic energy level exhibits redshift. In our approach for the Coulomb term between electron and hole, the Poisson–Schrödinger equations are solved self-consistently in the Hartree approximation. Subsequently, exciton binding energies and associated optical properties are computed. The results are presented as a function of QD radii and photon energies. We conclude that all of these numerical results are in agreement with the experimental studies. © 2009 American Institute of Physics . f DOI: 10.1063/1.3197034 g I. INTRODUCTION Recent developments in material synthesis and growth have made strong confinement of excitons possible in semi- conductor low-dimensional structures f e.g., quantum wires, quantum dots s QDs dg . 1 – 3 In such strong confinement regime, the quantum mechanical effects dominate with diminishing size of these nanostructures. These effects provide different advantages in designing new generation electronic and opti- cal devices including QD infrared photodetectors, light emit- ting diodes, and optical memories....
View Full Document

Page1 / 5

makale9_JAP_2009_HVD - Self-consistent computation of...

This preview shows document pages 1 - 2. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online