TY - JOUR AB - We report a systematic study of the photoluminescence properties of ZnO nanostructures. In particular, mesoporous ZnO powders of varying surface-to-mass ratio are investigated and compared to a bulk reference. At low temperatures the emission from higher-energy states is very pronounced and even dominant for samples with high surface-to-mass ratio. AU - Schwalm, Michael AU - Horst, Swantje AU - Chernikov, Alexej AU - Rühle, Wolfgang W. AU - Lautenschläger, Stephan AU - Klar, Peter J. AU - Meyer, Bruno K. AU - Waitz, Thomas AU - Tiemann, Michael AU - Chatterjee, Sangam ID - 25977 JF - physica status solidi (c) SN - 1610-1634 TI - Time-resolved photoluminescence study of mesoporous ZnO nanostructures ER - TY - JOUR AB - The recently developed two-dimensional Fourier-Transform-Spectroscopy (2DFTS) in the optical regime has been established as an elegant experiment, which has manifold of applications in the investigation of semiconductor nanostructures. Here we focus on the real and imaginary part 2DFT spectra. As predicted recently, using rephasing and non-rephasing modes, we are able to determine the homogeneous and inhomogeneous broadenings of coupled excitonic resonances even for weak disorder where photon-echo data are not useful. Computed real and imaginary parts of the 2DFTS for rephasing and non-rephasing modes are compared with experimental data of a GaAs quantum well. It is demonstrated, that phase sensitive data for the rephasing and non-rephasing modes are able to accurately provide the disorder induced broadening in a complex coupled system for each transition separately. AU - Kuznetsova, Irina AU - Thomas, Peter AU - Meier, Torsten AU - Zhang, Tianhao AU - Cundiff, Steven T. ID - 24983 IS - 2 JF - physica status solidi (c) SN - 1610-1634 TI - Determination of homogeneous and inhomogeneous broadenings of quantum-well excitons by 2DFTS: An experiment-theory comparison VL - 6 ER - TY - JOUR AB - A microscopic analysis of the emitted radiation of a semiconductor nanostructure after excitation with an extremely intense ultrashort laser pulse is presented. It is shown that the extreme nonlinear optical response is not sufficiently described by pure interband transitions but one has to include intraband effects as well. Numerical solutions of extended Bloch equations that include the coupled inter- and intraband dynamics are presented. For large excitation intensities, the intraband effects strongly modify the polarization dynamics and lead to a strong enhancement of high-harmonic generation compared to pure interband dynamics. AU - Golde, Daniel AU - Meier, Torsten AU - Koch, Stephan W. ID - 24982 IS - 2 JF - physica status solidi (c) SN - 1610-1634 TI - Microscopic analysis of high-harmonic generation in semiconductor nanostructures VL - 6 ER - TY - JOUR AB - Phonon-assisted singlet-singlet relaxation in semiconductor quantum dot molecules is studied theoretically. Laterally coupled quantum dot structures doped with two electrons are considered. We take into account interaction with acoustic phonon modes via deformation potential and piezoelectric coupling. We show that piezoelectric mechanism for the considered system is of great importance and for some ranges of quantum dot molecule parameters is the dominant contribution to relaxation. It is shown that the phonon-assisted tunneling is much faster (down to ∼ 6 ps even at zero temperature) in comparison with other decoherence processes. The influence of Coulomb interaction is discussed and its consequences are indicated. We calculate the relaxation rates for GaAs quantum dot molecules and study the dependence on quantum dot size, distance and offset between the constituent quantum dots. In addition the temperature dependence of the tunneling rates is analyzed. AU - Grodecka, Anna AU - Machnikowski, Paweł AU - Förstner, Jens ID - 4317 IS - 2 JF - physica status solidi (c) KW - tet_topic_qd SN - 1610-1634 TI - Theoretical study of phononassisted singlet-singlet relaxation in two-electron semiconductor quantum dot molecules VL - 6 ER - TY - JOUR AU - Richter, M. AU - Hugues, M. AU - Damilano, B. AU - Massies, J. AU - Duboz, J.-Y. AU - Reuter, Dirk AU - Wieck, A. D. ID - 8666 JF - physica status solidi (c) SN - 1610-1634 TI - 1.5 µm luminescence from InAs/GaxIn1–xNyAs1–y quantum dots grown on GaAs substrate ER - TY - JOUR AU - Greilich, A. AU - Oulton, R. AU - Zhukov, E. A. AU - Yugova, I. A. AU - Yakovlev, D. R. AU - Bayer, M. AU - Shabaev, A. AU - Efros, Al. L. AU - Merkulov, I. A. AU - Stavarache, V. AU - Reuter, Dirk AU - Wieck, A. ID - 8673 JF - physica status solidi (c) SN - 1610-1634 TI - Electron spin coherence in singly charged (In,Ga)As/GaAs quantum dots ER - TY - JOUR AB - We theoretically study the biexciton-phonon interaction in strongly confined semiconductor quantum dots. For spectrally narrow single-pulse excitation generation of biexcitonic occupations is only possible via a two-photon cascade, which exhibits renormalized Rabi oscillations and spectrally compressed phononsidebands. AU - Förstner, Jens AU - Knorr, A. AU - Moloney, J. V. ID - 4189 IS - 7 JF - physica status solidi (c) KW - tet_topic_qd SN - 1610-1634 TI - Interplay of electron-phonon and Coulomb interaction in semiconductor quantum dots VL - 3 ER - TY - JOUR AU - Tikhodeev, S. G. AU - Gippius, N. A. AU - Christ, A. AU - Zentgraf, Thomas AU - Kuhl, J. AU - Giessen, H. ID - 1748 IS - 2 JF - physica status solidi (c) SN - 1610-1634 TI - Waveguide-plasmon polaritons in photonic crystal slabs with metal nanowires VL - 2 ER - TY - JOUR AU - Haberer, E. D. AU - Meier, Cedrik AU - Sharma, R. AU - Stonas, A. R. AU - DenBaars, S. P. AU - Nakamura, S. AU - Hu, E. L. ID - 7676 IS - 7 JF - physica status solidi (c) SN - 1610-1634 TI - Observation of high Q resonant modes in optically pumped GaN/InGaN microdisks fabricated using photoelectrochemical etching VL - 2 ER - TY - JOUR AU - Schmidt, R. AU - Scholz, U. AU - Vitzethum, M. AU - Fix, R. AU - Malzer, S. AU - Metzner, C. AU - Kailuweit, P. AU - Reuter, Dirk AU - Wieck, A. AU - Hübner, M. C. AU - Stufler, S. AU - Zrenner, A. AU - Döhler, G. H. ID - 8689 JF - physica status solidi (c) SN - 1610-1634 TI - Single quantum dot nano-LEDs - spectroscopy of an electrically controlled few-particle system ER - TY - JOUR AU - Fühner, C. AU - Keyser, U. F. AU - Haug, R. J. AU - Reuter, Dirk AU - Wieck, A. D. ID - 8717 JF - physica status solidi (c) SN - 1610-1634 TI - Fano resonances in semiconductor quantum dots ER - TY - JOUR AB - The nonlinear propagation of subpicosecond pulses resonant to the hh 1s exciton in Bragg-periodic multiple quantum wells is investigated experimentally and theoretically. We show coherent pulse breakup and its suppression for increasing pulse intensity in good agreement with calculations based on the semiconductor Maxwell-Bloch equations. For highly nonlinear excitation, pulse compression is observed which is strongly enhanced by the additional contribution of self-phase modulation in the barrier and substrate material. AU - Nielsen, N. C. AU - Kuhl, J. AU - Schaarschmidt, M. AU - Förstner, Jens AU - Knorr, A. AU - Koch, S. W. AU - Gibbs, H. M. AU - Khitrova, G. AU - Giessen, H. ID - 4290 IS - 5 JF - physica status solidi (c) KW - tet_topic_qw SN - 1610-1634 TI - Pulse propagation in Bragg-resonant multiple quantum wells: from pulse breakup to compression ER - TY - JOUR AB - We present the experimental observation and the theoretical modelling of self-induced transparency signatures such as nonlinear transmission, pulse retardation and reshaping for subpicosecond pulse propagation in a 2 mm-long InGaAs quantum-dot ridge waveguide at 10 K. The measurements were obtained using a cross-correlation frequency resolved optical gating technique which allows us to retrieve the field amplitude of the propagating pulses. AU - Schneider, S. AU - Borri, P. AU - Langbein, W. AU - Woggon, U. AU - Förstner, Jens AU - Knorr, A. AU - Sellin, R. L. AU - Ouyang, D. AU - Bimberg, D. ID - 4322 IS - 5 JF - physica status solidi (c) KW - tet_topic_qd SN - 1610-1634 TI - Self-induced transparency in InGaAs quantum dot waveguides ER -