Optical properties of a semiconductor quantum well in the vicinity of a two-dimensional photonic crystal are investigated. Due to the periodic spatial modulation of the dielectric environment the effective Coulomb interaction potential exhibits the periodicity of the photonic crystal. As a consequence, the excitonic binding energy varies periodically by up to 50% depending on the spatial position of the exciton relative to the structured dielectric. The self image charge effects result in a position dependent shift of the single-particle bandgap such that the spectral position of the absorption spectrum also develops the periodicity of the photonic surrounding. (C) 2003 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

In this contribution, a Monte-Carlo computer simulation of phonon-assisted relaxation processes of excitons in CdSe/ZnSe quantum islands is presented. With the same set of parameters, it was possible to reproduce both the temperature dependence of the energy position and of the full width at half maximum (FWHM) of the luminescence emitted from a ZnCdSe quantum film containing 5 to 10 nm wide Cd-rich islands. With help of the model, the energy dependence of the distribution of the localized states is shown to be weaker than Gaussian. Furthermore, the obtained fitting parameters give evidence for an intra-island excitonic relaxation. Finally, our results, based on a realistic description of the exciton kinetics, are compared with those of a rate equation model.

Absorption spectra of semiconductor structures in photonic crystal environments are investigated numerically. It is shown that the periodic dielectric structuring changes the local optical and Coulomb interaction properties of semiconductor electron–hole excitations. The structurally induced modifications offer the possibility to design important aspects of the optoelectronic semiconductor properties.

We present a derivation of Forster coupling between two quantum dots by solving the equation of motion for the material excitation simultaneously with Maxwells equations. This allows us to identify the Forster process with the short-range contribution of the coupling that is mediated by the total electric field. The dependence of the coupling on the distance R of the dots is proportional to R-3, i.e. the rates follow the well-known R-6 behaviour. For distances between the sites longer than a quarter of the wavelength of light there is a cross-over to coupling due to the retarded light field, which is, proportional to R-1 i.e. the rates are proportional to R-2.

Get PDF Email Share Share with Facebook Tweet This Post on reddit Share with LinkedIn Add to CiteULike Add to Mendeley Add to BibSonomy Get Citation Copy Citation Text S.W. Koch, T. Stroucken, R. Eichmann, M. Kira, and W. Hoyer, "Photonic Structures: Exciton Effects in Photonic Crystal Structures," Optics & Photonics News 13(12), 48-48 (2002) Export Citation BibTex Endnote (RIS) HTML Plain Text Citation alert Save article

Induced surface polarizations are shown to cause significant modifications of the Coulomb interaction potential in photonic crystals. Because the optical properties are dominated by pair states, the locally varying electron–hole correlations induce a space dependence of the optical material response that strongly alters the emission and absorption characteristics. The possibility of designing the pair properties opens novel ways to manipulate the light–matter interaction in dielectric structures.

Macro- and micro-photoluminescence (PL) spectroscopy has been applied to investigate the exciton localization in cubic CdS/ZnSe type-II superlattices (SL) in the temperature range 5-35 K. The non-monotonic shift of the macro-FL peak with increasing temperature reveals the kinetic contribution of acoustic-phonon-assisted exciton multi-hopping processes. The experimental data are described by means of computer simulation and calculations based on a kinetic theory generalized from zero to finite temperatures. The advantages of each theoretical approach are discussed.

We show that interaction-assisted modes of transport play a role in the energy relaxation of excitons in disordered GaAs quantum wells. Semitransparent gold films are found to induce a blue shift in the photoluminescence spectrum of disordered wells. We interpret the result in terms of a long-range electromagnetic hopping coupling suppressed by image dipoles in the gold. The results are supported by Monte Carlo simulations of electromagnetically-assisted exciton hopping using hop rates modified by the gold layer.

We compute the time-resolved and steady-state recombination spectra for excitons in disordered semiconductor strips on the basis of hopping theory. Exciton hopping undergoes a dimensional crossover when the hop length is comparable to the strip width. We show by Monte Carlo simulation that the analysis of time-resolved photoluminescence spectra for strips of differing widths provides a measurement of the parameters of the hopping theory and permits a determination of the hopping mechanism.

Using time-resolved photoluminescence experiments and Monte Carlo simulation, we identify two distinct temperature regimes in the energy relaxation of excitons in a GaAs/AlGaAs double quantum structure. Below a critical temperature. the system is glassy and exhibits slow, nonexponential energy relaxation to the longest times observed. At higher temperatures, the system achieves thermal equilibrium in finite time. The transition between these regimes is marked by a dramatic critical behavior: a dynamical broadening of the energy distribution at the glass temperature. Simulations reproduce this critical behavior and allow for the first time the determination of the density of localized states.

Optical spectra in quantum wells are in many cases strongly influenced by disorder. In particular, energy relaxation of correlated electron-hole pairs through disorder-induced localized states determines the position and shape of photoluminescence lines. By a Monte Carlo simulation approach the energy relaxation is studied and the temperature dependence of the spectral peak and the linewidth are determined for a variety of model systems in the steady-state situation.

physica status solidi (b)Volume 205, Issue 2 p. R19-R20 Rapid Research Note Temperature–Dependent Exciton Luminescence in Coupled Quantum Wells S. D. Baranovskii, S. D. Baranovskii Institut für Physikalische Chemie und Zentrum für Materialwissenschaften der Philipps-Universität Marburg, D-35032 Marburg, GermanySearch for more papers by this authorR. Eichmann, R. Eichmann Fachbereich Physik und Zentrum für Materialwissenschaften der Philipps-Universität Marburg, D-35032 Marburg, GermanySearch for more papers by this authorP. Thomas, P. Thomas Fachbereich Physik und Zentrum für Materialwissenschaften der Philipps-Universität Marburg, D-35032 Marburg, GermanySearch for more papers by this author S. D. Baranovskii, S. D. Baranovskii Institut für Physikalische Chemie und Zentrum für Materialwissenschaften der Philipps-Universität Marburg, D-35032 Marburg, GermanySearch for more papers by this authorR. Eichmann, R. Eichmann Fachbereich Physik und Zentrum für Materialwissenschaften der Philipps-Universität Marburg, D-35032 Marburg, GermanySearch for more papers by this authorP. Thomas, P. Thomas Fachbereich Physik und Zentrum für Materialwissenschaften der Philipps-Universität Marburg, D-35032 Marburg, GermanySearch for more papers by this author First published: 29 January 1999 https://doi.org/10.1002/(SICI)1521-3951(199802)205:23.0.CO;2-DCitations: 7AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onEmailFacebookTwitterLinkedInRedditWechat No abstract is available for this article. References 1 T. Fukuzawa, E. E. Mendez, and J. M. Hong, Phys. Rev. Lett. 64, 3066 (1990). 2 J. A. Kash, M. Zachau, E. E. Mendez, J. M. Hong, and T. Fukuzawa, Phys. Rev. Lett. 66, 2247 (1991). 3 A. G. Abdukadyrov, S. D. Baranovskii, S. Yu. Verbin, E. L. Ivchenko, A. Yu. Naumov, and A. N. Reznitskii, Soviet Phys. - JETP 71, 1155 (1989). Citing Literature Volume205, Issue2February 1998Pages R19-R20 ReferencesRelatedInformation