Interface transfer processes and spectral hole burning in CdSe quantum confined clusters

Woggon, U.; Rückmann, I.; Kornack, J.; Müller, Michael; Cesnulevicius, J.; Petrauskas, M.; Kolenda, J.

doi:10.1016/0022-0248(92)90823-2

Cited by 15 publications

(6 citation statements)

References 21 publications

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“…The additional study of the luminescent Stokes shift and the degenerate four-wave mixing confirmed the value of S 1 which seems to be the common property of all the glasses studied in Refs. [6][7][8][9][10][11]. Though the value of 17 meV reported for colloidal particles is much smaller than the same value observed in semiconductor doped glasses, it is still considerably larger than expected from the theory5 .…”

Section: Introductionmentioning

confidence: 67%

Spectrally-narrow nonlinear resonances in semiconductor-doped glasses

et al. 1993

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For the first time we report spectral hole-burning with the width as small as r=io meV for semiconductor quantum dots of the size much smaller than the excitonic Bohr radius of the bulk material. The narrow nonlinear resonances found, are typical of the structures prepared at the nucleation and nomal growth precipitation stages. The saturation intensity of the order of 102 kW/cm registered for high-quality CdSe-doped glass is close to that for excitonic nonlinearity of CdSe monocrystalline films. The structures grown at the coalescence stage show only broad-band nonlinear absorption with a saturation intensity much more higher than the proper bulk material.

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Section: Introductionmentioning

confidence: 67%

Spectrally-narrow nonlinear resonances in semiconductor-doped glasses

et al. 1993

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“…In glasses, experiments are rare which give a direct comparison o f nonlinearoptics before and after a controlled interface modification. Changes o f the optical nonlinearity after controlled surface passivation by hydrogenation have been established for CdSe quantum dots in borosilicate glass matrix [48,49]. Over-barrier transitions o felectrons out ofthe quantum dot into the glass have been proven by measuring the thermo-stimulated luminescence o f semiconductor-doped glasses [50].…”

Section: Dynamics O F Trapping and Photodarkeningmentioning

confidence: 99%

“…The models presentedto explain the recombination dynamics of II-VI QDs embedded in organics or glasses can be classified in (i) three-or four-level systems without taking into account photodarkening [13,42] and (ii) modified three level systems including photodarkening by either the intensity-dependent activation o f a new trap state [43,44] or two-step absorption to excited states followed by the transfer into the glass matrix [45,48,49]. In addition, Auger processes have been considered in [47,50,52].…”

Section: Dynamics O F Trapping and Photodarkeningmentioning

confidence: 99%

“…Its population is more probably from the excited states of the quantum dot and trapping can be followed by transfer processes into the glass matrix. By means o f a two-step excitation process (photoassisted trapping) electrons and holes populate states within the Figure 12 Calculated time behaviour of the nonlinear transmissionof a quantum dot sample after ps-excitation modeled for a two-beam experiment according to the scheme with 7-0 = 300 ps, tT1 -~8 × 10 -17 cm2, o' :z --4 × 10-16 cm~and r" >> r eap for both electrons and holes [49].…”

Section: Dynamics O F Trapping and Photodarkeningmentioning

confidence: 99%

“…A shortening of the fast component -as it was observed in Fig. 11 -could be achieved only by changing the cross-section~r (increasing induced absorption) and the capture time rcap without any modification in the electron-hole recombination time T0 (for more details see [49]). Experimentscarried out by modifying the interface properties [48] reflected the predicted behaviour.…”

Section: Dynamics O F Trapping and Photodarkeningmentioning

confidence: 99%

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Dynamics of optical excitations in quantum dots of wide-gap semiconductors

Woggon

Advances in Solid State Physics 35

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Quantum dots made from II-VI and I-VII semiconductors and embedded in glasses have been investigated by means of linear and nonlinear optical methods. The different experiments cover the time range between a few tens of femtoseconds up to nanoseconds and seconds. The studies comprise the ultrashort phase relaxation times, the gain build-up and decay times, the one-and two-pair direct recombination times as well as the long-time range, which is dominated by trap processes.

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Homogeneious linewidth and relaxation of excited hole states in II–VI quantum dots

Woggon

Гапоненко

Uhrig

et al. 1994

Adv Material for Optics Elec

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By use of differential absorption spectroscopy at different temperatures we investigate the homogeneous line broadening of small CdSxSelquantum dots embedded in glass. Our experiments show the strong correlation between the precipitation stages and characteristic optical parameters such as the saturation intensity and the longitudinal and transverse relaxation times. In samples grown in the diffusion-controlled regime to avoid coalescence, we find after strong laser excitation for the first time spectrally narrow holes in the non-linear differential absorption spectra. These sharp non-linear resonances with a halfwidth r of only 10 meV at T = 20 K allow us to investigate the energetic distance of the lowest hole levels and the temperature dependence of the line broadening. The different contributions of LO phonon coupling and temperature-independent scattering to the homogeneous linewidth will be analysed. The relaxation from the excited hole states has been investigated by exciting in the higher-energy hole states and measuring the resulting change in the ground state absorption.

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Interface transfer processes and spectral hole burning in CdSe quantum confined clusters

Cited by 15 publications

References 21 publications

Spectrally-narrow nonlinear resonances in semiconductor-doped glasses

Spectrally-narrow nonlinear resonances in semiconductor-doped glasses

Dynamics of optical excitations in quantum dots of wide-gap semiconductors

Homogeneious linewidth and relaxation of excited hole states in II–VI quantum dots

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