AVS 52nd International Symposium
    Electronic Materials and Processing Thursday Sessions
       Session EM2-ThM

Paper EM2-ThM6
Modeling of InAs/GaAs Self-Assembled Heterostructures: Quantum Dot to Quantum Ring Transformation

Thursday, November 3, 2005, 10:00 am, Room 310

Session: Heteroepitaxy and Low-Dimensional Structures
Presenter: I. Filikhin, North Carolina Central University
Authors: I. Filikhin, North Carolina Central University
E. Deyneka, North Carolina A&T State University
B. Vlahovic, North Carolina Central University
Correspondent: Click to Email
It is possible to directly observe discreet energy spectra of self-assembled quantum dots (QD) and quantum rings (QR) by means of capacitance-voltage (CV) spectroscopy.@footnote 1,2@ Related theoretical studies, however, had some difficulties interpreting the experiments. Acquired values of the electron effective mass in QD@footnote 1@ and QR@footnote 2,3@ were significantly larger than the bulk mass. Also, the value of the energy-gate-voltage conversion coefficient was in disagreement with experimental conditions.@footnote 2,3@ In presented work we use relatively simple single subband model for InAs/GaAs QD(QR) where the energy dependence of electron effective mass is defined by the Kane formula.@footnote 4@ Model assumptions lead to the non-linear Schrodinger equation in 3D space.@footnote 5@ Model geometrical parameters are based on the fabrication process for InAs/GaAs QD/QR,@footnote 6@ for which the experimental CV data is available.@footnote 1,2@ We assume that the QD to QR transformation occurs without the loss of InAs material. Energies of confinement states of QD(QR) are calculated. Obtained results for single energy levels are in good agreement with the CV spectroscopy.@footnote 1,2@ Our calculations reproduce experimental value for the energy-gate-voltage conversion coefficient as 7. Magnitude of the non-parabolic contribution to the electron effective mass is also evaluated. @FootnoteText@ @footnote 1@ B. T. Miller, et al., Phys. Rev. B 56, 6764 (1997).@footnote 2@ A. Lorke, et al., Phys. Rev. Lett. 84, 2223 (2000).@footnote 3@ A. Emperador, et al., Phys. Rev. B. 62, 4573 (2000).@footnote 3@ E. Kane, J. Physics and Chemistry of Solids 1 249 (1957).@footnote 4@ Li Y, et al., Journal Applied Physics 90 6416 (2002).@footnote 5@ I. Filikhin, E. Deyneka and B. Vlahovic, Model. Simul. Mater. Sci. Eng. 12, 1121 (2004).@footnote 6@ J.M. Garsia et al., Appl. Phys. Lett. 71, 2014 (1997).