Reversible adsorption-enhanced quantum confinement in semiconductor quantum dots

Sarkar, Shaibal K.; Chandrasekharan, Nirmala; Gorer, Sasha; Hodes, Gary
December 2002
Applied Physics Letters;12/23/2002, Vol. 81 Issue 26, p5045
Academic Journal
Semiconductor quantum dots possess two important properties: Size-dependent increase in band gap (size quantization) and a very high surface-to-volume ratio. We show that cyanide adsorption on this high surface further increases the size quantization in films of CdSe and CdS quantum dots and that removal of the cyanide reverses this effect. This effect is explained by increased localization due to compression of the electron wave function in the dots by the strongly adsorbed [on both Cd and Se(S)] negatively charged cyanide.


Related Articles

  • Selective excitation of the photoluminescence and the energy levels of ultrasmall InGaAs/GaAs.... Fafard, S.; Leonard, D. // Applied Physics Letters;9/12/1994, Vol. 65 Issue 11, p1388 

    Investigates the energy levels of nanometer size indium gallium arsenide/ GaAs quantum dots (QD) and selective excitation of the photoluminescence. Synthesis of QD structures with diameters comparable to electrons' de Broglie wavelength; Use of coherent islanding growth effect in highly...

  • Evolution of the energy levels in quantum dot ensembles with different densities. Fafard, S.; Wasilewski, Z.R.; Spanner, M. // Applied Physics Letters;9/27/1999, Vol. 75 Issue 13, p1866 

    Discusses the evolution of the energy levels in quantum dot ensembles with different densities. Lateral interactions for quantum dot spacings of hundreds of nanometers; Decrease in the photoluminescence intensity.

  • Size quantization effects in InAs self-assembled quantum dots. Schmidt, K.H.; Medeiros-Ribeiro, G.; Garcia, J.; Petroff, P.M. // Applied Physics Letters;3/31/1997, Vol. 70 Issue 13, p1727 

    Analyzes the size quantization effects in indium arsenide (InAs) self-assembled quantum dots (QD) in gallium arsenide. Correlation of quantized level energies with QD sizes and densities; Impact of InAs coverage on QD thickness; Separation of the excited electron hole pairs by the electric...

  • The Energy Spectrum of Charge Carriers in a Strongly Oblate Ellipsoidal Quantum Dot. Zegrya, G. G.; Konstantinov, O. V.; Matveentsev, A. V. // Technical Physics Letters;Aug2002, Vol. 28 Issue 8, p693 

    A new method of introducing curvilinear coordinates for an oblate ellipsoid of revolution is developed, which is valid for charge carriers obeying a parabolic isotropic dispersion law. Using this method, simple analytical formulas are derived for the energy spectrum of carriers in an oblate...

  • Electron energy state dependence on the shape and size of semiconductor quantum dots. Li, Yiming; Voskoboynikov, O.; Lee, C. P.; Sze, S. M.; Tretyak, O. // Journal of Applied Physics;12/15/2001, Vol. 90 Issue 12, p6416 

    In this article we present a unified model for studying the effect of the sizes and shapes of small semiconductor quantum dots on the electron and hole energy states. We solved the three-dimensional effective one band Schrödinger equation for semiconductor quantum dots with disk, lenticular,...

  • Identification of atomic-like electronic states in indium arsenide nanocrystal quantum dots. Banin, Uri; Cao, YunWei; Katz, David; Millo, Oded // Nature;8/5/1999, Vol. 400 Issue 6744, p542 

    Reports the results of a study which examines indium arsenide nanocrystal quantum dots. Use of cryogenic scanning tunnelling spectroscopy; Semiconductor quantum dots as marking the transition between molecular and solid-state regimes; Their expression of atomic-like symmetries, for example `s'...

  • Energy level control for self-assembled InAs quantum dots utilizing a thin AlAs layer. Kim, J. S.; Yu, P. W.; Leem, J. Y.; Lee, J. I.; Noh, S. K.; Kim, Jong Su; Kim, S. M.; Son, J. S.; Lee, U. H.; Yim, J. S.; Lee, D. // Applied Physics Letters;5/21/2001, Vol. 78 Issue 21, p3247 

    Ground-state energy of InAs quantum dots (QDs) in the GaAs matrix can be changed significantly by introducing a thin AlAs layer (1 nm). The photoluminescence (PL) peak position of the QDs grown directly on the thin AlAs layer is blueshifted by 171 meV from that of the QDs grown without the AlAs...

  • Lasing from InGaAs/GaAs quantum dots with extended wavelength and well-defined harmonic-oscillator energy levels. Park, G.; Shchekin, O. B.; Huffaker, D. L.; Deppe, D. G. // Applied Physics Letters;12/7/1998, Vol. 73 Issue 23 

    Data are presented on the lasing transitions from InGaAs/GaAs quantum dots that exhibit four well-resolved energy transitions, with the electronic state density of a two-dimensional harmonic oscillator. Lasing has been obtained on the second and third transitions, depending on the cavity (gain)...

  • Theory of a room-temperature silicon quantum dot device as a sensitive electrometer. Vincent, J.K.; Narayan, V.; Pettersson, H.; Willander, M.; Jeppson, K.; Bengtsson, L. // Journal of Applied Physics;1/1/2004, Vol. 95 Issue 1, p323 

    We consider theoretically the use of a room-temperature silicon quantum dot based device for electrometer applications. The low power device includes two split gates that quantize the electronic energy levels in the emitter and collector regions. The base consists of a silicon quantum dot buried...


Read the Article


Sorry, but this item is not currently available from your library.

Try another library?
Sign out of this library

Other Topics