Full-text resources of PSJD and other databases are now available in the new Library of Science.
Visit https://bibliotekanauki.pl
Preferences help
Polish version English version Language
enabled [disable] Abstract
Number of results

Results found: 8

Number of results on page
first rewind previous Page / 1 next fast forward last

Search results

help Sort By:

help Limit search:
first rewind previous Page / 1 next fast forward last
1
Content available remote

Excitation and Recombination Processes in InAs_{x}P_{1-x}:Yb (x=0.04, 0.07 and 0.11)

100%
Godlewski M., Kozanecki A., Karpińska K., Bergman J. P., Monemar B.
Acta Physica Polonica A
|
1995
|
vol. 87
|
issue 1
217-220
EN
Excitation and recombination mechanisms of Yb^{3+} 4f-4f intra-shell emission in InP and InAsP (4, 7 and 11% of As) are analyzed.
2
Content available remote

Theoretical and Experimental Study of the Radiative Decay Process in a Modulation Doped GaAs/AlGaAs Heterointerface

86%
Lundström T., Bergman J. P., Holtz P. O., Monemar B., Campman K., Merz J. L., Gossard A. C.
Acta Physica Polonica A
|
1997
|
vol. 92
|
issue 4
824-828
EN
We have theoretically and experimentally investigated the radiative recombination process in an n-type modulation doped GaAs/Al_{0.35}Ga_{0.65}As heterostructure. The dynamical reshaping of the potential profile across the heterojunction, and the decay of the spatially indirect radiative recombination between electrons in the two-dimensional electron gas and photo-created holes, have been numerically simulated for various values of the electric field across the heterojunction. Optical matrix elements were deduced from a self-consistent solution of the coupled Schrodinger and Poisson equations at every discrete point of time. The calculated recombination energies and integrated luminescence intensities were compared with experimental data from time-resolved photoluminescence measurements on an 800 Å wide GaAs/AlGaAs heterostructure.
3
Content available remote

Influence of Growth Conditions on Exciton Properties in Thin Quantum Wells of GaAs/AlGaAs

86%
Godlewski M., Bergman J. P., Holtz P. O., Monemar B., Bugajski M., Regiński K., Kaniewska M.
Acta Physica Polonica A
|
1995
|
vol. 88
|
issue 4
719-722
EN
Exciton properties in growth interrupted quantum wells of GaAs/AlGaAs are compared with those observed for structures grown with­out growth interruption during the molecular beam epitaxy process. We report observation of quasi-localized excitons in quantum well structures grown without growth interruptions. Quasi-localized excitons drift towards the states of a lower potential energy in the quantum well. For growth in­terrupted MBE structures islands with a constant quantum well thickness become large compared to the exciton radius. Free or lightly localized exci­tons are observed in that case.
4
Content available remote

Optically Detected Cyclotron Resonance Studies of CdMnTe/CdTe Multiquantum Wells and CdMgTe/CdMnTe Superlattices

86%
Godlewski M., Świątek K., Harris C. I., Bergman J. P., Monemar B., Waag A.
Acta Physica Polonica A
|
1995
|
vol. 87
|
issue 1
213-216
EN
The results of photoluminescence, time resolved photoluminescence (de­cay times), optically detected cyclotron and magnetic resonances investiga­tions of CdMnTe/CdTe multiquantum wells and CdMgTe/CdMnTe super-lattices are presented. The role of defects and quantum well width fluctua­tions in recombination processes of 2D carriers is discussed.
5
Content available remote

Recombination Processes in Doped CdTe/CdMnTe Multiple Quantum Well Structures Grown by Molecular Beam Epitaxy

86%
Godlewski M., Wojtowicz T., Karczewski G., Kossut J., Bergman J. P., Monemar B.
Acta Physica Polonica A
|
1997
|
vol. 92
|
issue 4
757-760
EN
An influence of doping level on exciton properties in n-doped multiple quantum well structures of CdTe/CdMnTe is studied for multiple quantum well structures prepared in the way that donor (indium) concentration changes within the length of the sample. We show that the formation scenario for neutral donor bound excitons in low-dimensional structures can be different from that observed in bulk samples. We further show that in the case of such quantum well structures we can selectively excite either photoluminescence emission of localized or donor bound excitons, which is a consequence of surprisingly weak energy transfer link between two types of excitonic transitions.
6
Content available remote

Hot Photoluminescence in CdTe/CdMnTe Quantum Well Structures Grown by Molecular Beam Epitaxy

86%
Godlewski M., Wojtowicz T., Karczewski G., Kossut J., Bergman J. P., Holtz P. O., Monemar B.
Acta Physica Polonica A
|
1997
|
vol. 92
|
issue 4
765-768
EN
A step-like emission is observed for CdTe/CdMnTe structures δ-doped with In. The new photoluminescence cannot be explained by neither the Raman process nor by the "ordinary" hot photoluminescence. We propose that magnetic interactions are responsible for the new photoluminescence appearing due to a dramatic increase in a thermalization time of hot excitons.
7
Content available remote

Exciton Dynamics in CdTe/CdMnTe Multiquantum Well Structures Grown by Molecular Beam. Epitaxy on GaAs Substrate

73%
Godlewski M., Koziarska B., Suchocki A., Karczewski G., Wojtowicz T., Kossut J., Bergman J. P., Monemar B.
Acta Physica Polonica A
|
1995
|
vol. 88
|
issue 5
985-989
EN
The results of picosecond photoluminescence kinetics of four different CdTe/CdMnTe multiquantum well structures grown by MBE on GaAs substrates are presented. The experimental results show that excitons in CdTe quantum wells are strongly localized by potential fluctuations. Photoluminescence decay times of the localized excitons are considerably shorter (about 120 ps) than those reported for free or quasi-free excitons. An influence of Mn in the barriers on exciton properties is demonstrated. For narrow quantum wells as well as for the multiquantum well structure with the highest Mn mole fraction the excitons migrate during their decay to the states with a lower potential energy. Longer decay times are observed for quasi-localized excitons. We show also that for strongly localized excitons the energy transfer between localized and donor bound excitons is less efficient.
8
Content available remote

Exciton Transfer in Multiple Quantum Well Structures of CdTe/CdMnTe Grown by Molecular Beam Epitaxy

73%
Godlewski M., Surma M., Wilamowski Z., Wojtowicz T., Karczewski G., Kossut J., Holtz P. O., Bergman J. P., Monemar B.
Acta Physica Polonica A
|
1997
|
vol. 92
|
issue 4
761-764
EN
The direct evidence for the efficient transfer of excitons from 4 nm and 6 nm to 10 nm wide CdTe quantum wells is presented based on the results of photoluminescence and photoluminescence excitation investigation. Efficient transfer is observed for quantum wells separated by thick (50 nm) CdMnTe barriers containing 10% or 30% Mn fraction. A new mechanism of the transfer is proposed, which involves long range dynamic magnetic interactions between free/bound excitons and Mn ions in the CdMnTe barrier regions of the structure.
first rewind previous Page / 1 next fast forward last
JavaScript is turned off in your web browser. Turn it on to take full advantage of this site, then refresh the page.