microscopy spectroscopy on quantum dots

... Excitonic Polarons in Semiconductor Quantum Dots Phys Rev Letts 2002, 88:146803 11 Seebeck J, Nielsen TR, Gartner P, Jahnke F: Polarons in semiconductor quantum dots and their role in the quantum ... Chacon R, Yang RQ: Lasing characteristics of InAs quantumdot lasers on (001) InP substrate Appl Phys Letts 2003, 83:1704 Prezhdo OV: Multiple excitons and the electron-phonon bottleneck in semiconductor ... phonon broadening [19] Efficient coupling to acoustic phonons exists not only for QD ground states but also for excited states For low temperature, in which the interaction with acoustic phonon...

Ngày tải lên: 21/06/2014, 03:20

... could be stronger than the type II transition due to the stronger spatial confinement of carriers in the QD and the nature of the direct transition type I transition It may be the reason that the ... Z, Xiong M, Zhao L: Strain accumulation in InAs/InxGa1−xAs quantum dots Appl Phys A 2011, 104:257 Wang ZhM, Seydmohamadi Sh, Lee JH, Salamo GJ: Surface ordering of (In, Ga)As quantum dots controlled ... recombination in type-II GaSb/GaAs quantum dots Appl Phys Lett 1995, 67:656 10 Alonso-Álvarez D, Alén B, García JM, Ripalda JM: Optical investigation of type II GaSb/GaAs self-assembled quantum dots...

Ngày tải lên: 20/06/2014, 20:20

... Effective one-dimensional electronic structure of InGaAs quantum dot molecules Microelectron Eng 2008, 85:1225-1228 Limwongse T, Panyakeow S, Kanjanachuchai S: Evolution of InAs quantum dots grown on ... Self-organization of (In, Ga)As/GaAs quantum dots on relaxed (In, Ga)As films Appl Phys Lett 1998, 73:2164-2166 Kim KM, Park YJ, Park YM, Hyon CK, Kim EK, Park JH: Alignment of InAs quantum dots on a controllable ... upon 10-min annealing Additional peak at around 1.5 eV emerges as a result of annealing This value corresponds to exciton combination in bulk GaAs Upon 30-min annealing, this bulk GaAs emission...

Ngày tải lên: 21/06/2014, 01:20

... limiting cases (strong and weak confinement) for onedimensional quantum dots The eigenfunctions and eigenvalues are presented in references [5] and [8] In one-dimensional case, the confinement potential ... Guo K-X: Exciton effects on the nonlinear optical rectification in one-dimesional quantum dots Phys Lett A 2005, 335:175 Baskoutas S, Paspalakis E, Terzis AF: Effects of excitons in nonlinear optical ... optical rectification in semi-parabolic quantum dots Phys Rev B 2006, 74:153306 Zhang C-J, Guo K-X, Lu Z-E: Exciton effects on the optical absorptions in one-dimensional quantum dots Phys E 2007,...

Ngày tải lên: 21/06/2014, 04:20

... biexciton peak XX, charged excitons, and higher excitonic complexes arise The exciton and biexciton peaks were identified on basis of their excitation power dependence (Fig 3a), with slope of one ... novel path for entangled photon generation using the time reordering scheme [26] Conclusions In conclusion, we have studied a novel type of strain-free GaAs quantum dots which are fabricated by ... reflects in addition electron– electron and hole–hole interactions This complex interplay depends sensitively on details of the QD morphology [7] QDs with low exciton–biexciton splitting are highly...

Ngày tải lên: 21/06/2014, 17:20

... bottom of the conduction band of GaSb QDs In such circumstance, the light emission intensity of the GaSb QD could be stronger than the type II transition due to the stronger spatial confinement of ... Z, Xiong M, Zhao L: Strain accumulation in InAs/InxGa1-xAs quantum dots Appl Phys A 2011, 104:257 Wang ZhM, Seydmohamadi Sh, Lee JH, Salamo GJ: Surface ordering of (In, Ga)As quantum dots controlled ... recombination in type-II GaSb/GaAs quantum dots Appl Phys Lett 1995, 67:656 10 Alonso-Álvarez D, Alén B, García JM, Ripalda JM: Optical investigation of type II GaSb/GaAs self-assembled quantum dots...

Ngày tải lên: 21/06/2014, 17:20

... three-dimensional quantum confined nature of the electronic spectra However, the randomness in their size as well as position on a planar substrate is undesirable particularly for electronic device ... applications, even though they produce these unique properties for the realization of quantum functional electron devices [1, 2] For this reason, many techniques have been proposed and attempted to control ... (SA-MOVPE) is one of the most effective approaches in fabrication of uniform and position-controlled QDs because appropriate patterning of the mask layer and control of the growth conditions enable...

Ngày tải lên: 21/06/2014, 17:20

... same material system That is, depending on the growth conditions, the elastic strain can be relaxed by the formation of either quantum wires or quantum dots, or even unique island–pit pairs The ... growth of QDs, pits and dots pits cooperative systems By the corresponding and independent variations of the Vgroup elements concentrations, the preferred nucleation of the dots or pits can be selected ... background electron concentration of n = 1016 cm-3 The InAs0,742Sb0,08P0,178 quaternary alloy used here as basis composite is conveniently lattice-matched to InAs The LPE growth solution components—undoped...

Ngày tải lên: 22/06/2014, 00:20

... bottom of the conduction band of GaSb QDs In such circumstance, the light emission intensity of the GaSb QD could be stronger than the type II transition due to the stronger spatial confinement of ... Z, Xiong M, Zhao L: Strain accumulation in InAs/InxGa1-xAs quantum dots Appl Phys A 2011, 104:257 Wang ZhM, Seydmohamadi Sh, Lee JH, Salamo GJ: Surface ordering of (In, Ga)As quantum dots controlled ... recombination in type-II GaSb/GaAs quantum dots Appl Phys Lett 1995, 67:656 10 Alonso-Álvarez D, Alén B, García JM, Ripalda JM: Optical investigation of type II GaSb/GaAs self-assembled quantum dots...

Ngày tải lên: 22/06/2014, 00:20

... expansion in the variations of the bond length and the angles between the bond and its nearest neighbor bonds Under the rubric of shortrange contributions and by following the general notations ... effect on the strain distribution in QD and the corresponding band offset The second one is the degree of anisotropy of elastic property, which is described by elastic constants In our calculation, ... different response wavelength as described in our calculation The results mean that one can obtain the ideal response wavelength of QDIP structure by controlling the growth condition to change...

Ngày tải lên: 22/06/2014, 01:20

... the misfit dislocation network The indicated axes are b parallel to h1" i directions and a parallel to h11" i directions 100 20 quantum dots it bends to lie parallel h0001i on a ð10" Þ 10 prismatic ... revealing that it consists of a set of three families of 60° MDs lying along the three main h1" i directions without interaction 210 between them The network consists of a mosaic of hexagonal and triangular ... R.B Nicholson, D.W Pashley, M.J Whelan, Electron Microscopy of Thin Crystals (Butterworths, London, 1965) 12 K Jacobi, Prog Surf Sci 71, 185 (2003) ¨ 13 M.J Hytch, T Plamann, Ultramicroscopy...

Ngày tải lên: 22/06/2014, 18:20

... resolution of 17 ps) All the measurements were performed at low excitation density, in order to overcome multiexciton generation Results and Discussion In Fig 1A the temporal evolution of CdSe/ZnS ... Such a time evolution suggests that three emitting states, with different relaxation times, contribute to the PL of these quantum dots We have fitted the PL spectra to a superposition of three lorentzian ... escape induced by optical phonons absorption To explain the behaviour up to 60 K, we have developed a four-level model (Fig 2B) By considering only thermal population effects in the range of 15–60...

Ngày tải lên: 22/06/2014, 18:20

... for that QD formation on the pure vicinal surfaces Conclusions In conclusion, InAs quantum structures simultaneously grown on GaAs (100), GaAs (100) with a 2° misorientation angle towards [01-1], ... affecting the kinetics of adsorption, migration, desorption, reconstruction, and strain relaxation In fact, the in-QD strain relaxation is influenced by the substrate orientation and it has been proven ... due to the strong 3D confinement, which demonstrates the *12 meV exciton binding energy in these dots Due to the fact that the excitons in the WL easily interacted with the phonon and quenched,...

Ngày tải lên: 22/06/2014, 19:20

... 10-9 M concentrations over the longer co-incubation times Thus, the 10-8 M QD concentration appears to act as a threshold for the initiation of deleterious effects At 10-9 M concentrations, there ... positive controls Little distinction is recorded at 72 hours illustrating the negative impact that prolonged co-incubation with the QDs has on cell proliferation at this concentration Similarly ... response varied in proportion to QD size, composition and concentration QD size significantly impacted measured responses For the alamarBlue and PicoGreen assays at 10-7 &-8 M QD concentrations,...

Ngày tải lên: 11/08/2014, 00:22

... Multicolor quantum dots for molecular diagnostics Fluorescence resonance energy transfer quenching Nonfluorescent dye A Excitation Quantum dot Pentahistadine tail Quantum dot Maltose MBP Nonfluorescent ... of intracellular localization of embedding and fixation processes Nonegrowth hormone and prolactin and their mRNA using quantum dots (Q and confocal laser scanning Ds) microscopy [46] (B) Microtubules ... MP Waggoner AS Noninvasive , imaging of quantum dots in mice Bioconjug Chem 15(1), 79–86 (2004) 54 55 Derfus AM, Chan WCW, Bhatia SN Probing the cytotoxicity of semiconductor quantum dots Nano...

Ngày tải lên: 15/02/2014, 05:20

... Duc Chinh, Vu Thi Hong Hanh, Synthesis CdSe quantumdots and determine its size from optical spectra, Advances in Optics Photonics Spectroscopy & Applications V (2008) 517 S.V.Gaponenko, Optical ... of the first excitonic absorption peak of the corresponding sample + The second one, we estimate the mean size of QDs by the Scherer’s formula [8]: r= kλ D cos θ (3) 209 K.C Cuong et al / VNU Journal ... distribution in particle size Besides that, the hydrothermal method requires the long time reaction and its distribution in particle size is in the broadening range In this article, we report on the...

Ngày tải lên: 14/03/2014, 13:20

... Equation o Derivation of the Schrădinger Equation o Boundary Conditions Particle Flux and Schrădinger Equation o Solution of the Free Particle Schrădinger o Particle in One-Dimensional ... Section we present the theory of manyboson and manyfermion systems in a formulation exploiting the algebra of the associated creation and annihilation operators Section provides an introduction ... of Quantum Mechanics, on scattering theory, on perturbation theory, on Stochastic Quantum Mechanics, and on the group theory of elementary particles will be added as well as the existing sections...

Ngày tải lên: 17/03/2014, 14:41

... common factor of both extensors The calculation of the Erg¨ nzung is one of the a most time consuming operation in geometrical computations based on meet and join operations 10 A Treatise on Quantum ... cliffordization to bilinear forms B which are not derivable from the exponenF tiation of a bilinear form on the generating space B • We discuss generalized cliffordization based on non-exponentially ... correlation functions based on dotted and undotted exterior wedge products), meet and join products, co-meet and co-join, left and right contraction by arbitrary elements, left and right co-contractions,...

Ngày tải lên: 31/03/2014, 15:07

... notation and formalism, time evolution of quantum systems, angular momentum theory, creation and annihilation operators (the second quantization representation), symmetries and conservation laws, ... Collision Theory 6.1 196 Collisions in one- and three-dimensions 197 6.1.1 One-dimensional square potential barriers 197 6.2 Collision in three dimensions ... Position Eigenkets and Position Measurements To extend the idea of a filtering process to measurements of observables exhibiting continues spectra, we consider the position operator in one dimension...

Ngày tải lên: 24/04/2014, 17:12

... coated CdTe quantum dots response to protoporphyrin-IX 38 3.3.3 Singlet oxygen detection using SOSG™, and CdTe quantum dots 39 3.4 Conclusion 46 LEAD SULFIDE QUANTUM DOTS AND ITS ... photons Therefore, deep level traps have a tendency to undergo nonradiative recombination by emitting phonons This non-radiative relaxation process consists of three types: internal conversion, ... conversion, external conversion or Auger recombination Internal conversion is the nonradiative recombination through crystalline and/or molecular vibrations, and is also one of the reasons for Stokes...

Ngày tải lên: 28/04/2014, 15:48