TY - JOUR AU - Marquardt, Bastian AU - Geller, Martin AU - Lorke, Axel AU - Reuter, Dirk AU - Wieck, Andreas D. ID - 7987 IS - 10 JF - Physica E: Low-dimensional Systems and Nanostructures SN - 1386-9477 TI - A two-dimensional electron gas as a sensitive detector to observe the charge carrier dynamics of self-assembled QDs VL - 42 ER - TY - JOUR AB - An intentional positioning of optically active quantum dots using site-selective growth by a combination of molecular beam epitaxy (MBE) and focused ion beam (FIB) implantation in an all-ultra-high-vacuum (UHV) setup has been successfully demonstrated. A square array of periodic holes on GaAs substrate was fabricated with FIB of 30 keV ions followed by an in situ annealing step. Subsequently, the patterned holes were overgrown with an optimized amount of InAs in order to achieve site-selective growth of the QDs on the patterned holes. Under well-optimized conditions, a selectivity of single quantum dot growth in the patterned holes of 52% was achieved. Thereafter, carrier injection and subsequent radiative recombination from the positioned InAs/GaAs self-assembled QDs was investigated by embedding the QDs in the intrinsic part of a GaAs-based p–i–n junction device. Electroluminescence spectra taken at 77 K show interband transitions up to the fifth excited state from the QDs. AU - Mehta, Minisha AU - Reuter, Dirk AU - Melnikov, Alexander AU - Wieck, Andreas D. AU - Michaelis de Vasconcellos, Steffen AU - Baumgarten, Tim AU - Zrenner, Artur AU - Meier, Cedrik ID - 4551 IS - 10 JF - Physica E: Low-dimensional Systems and Nanostructures KW - Molecular beam epitaxy KW - Focused ion beam KW - Self-assembled quantum dot KW - Electroluminescence SN - 1386-9477 TI - Intentionally positioned self-assembled InAs quantum dots in an electroluminescent p–i–n junction diode VL - 42 ER - TY - JOUR AB - Here we report on investigations on CdSe quantum dots incorporated in ZnSe based Schottky photodiodes with near-field shadow masks. Photoluminescence and photocurrent of individual quantum dots were studied as a function of the applied bias voltage. The exciton energy of the quantum dot ground state transition was shifted to the excitation energy by using the Stark effect tuning via an external bias voltage. Under the condition of resonance with the laser excitation energy we observed a resonant photocurrent signal due to the tunnelling of carriers out of the quantum dots at electric fields above 500 kV/cm. AU - Panfilova, M. AU - Michaelis de Vasconcellos, S. AU - Pawlis, A. AU - Lischka, K. AU - Zrenner, Artur ID - 4552 IS - 10 JF - Physica E: Low-dimensional Systems and Nanostructures KW - CdSe/ZnSe quantum dots KW - Photodiode KW - Quantum confined Stark Effect KW - Photocurrent KW - II–VI Semiconductors SN - 1386-9477 TI - Resonant photocurrent-spectroscopy of individual CdSe quantum dots VL - 42 ER - TY - JOUR AU - Piegdon, Karoline A. AU - Offer, Matthias AU - Lorke, Axel AU - Urbanski, Martin AU - Hoischen, Andreas AU - Kitzerow, Heinz-Siegfried AU - Declair, Stefan AU - Förstner, Jens AU - Meier, Torsten AU - Reuter, Dirk AU - Wieck, Andreas D. AU - Meier, Cedrik ID - 7993 IS - 10 JF - Physica E: Low-dimensional Systems and Nanostructures SN - 1386-9477 TI - Self-assembled quantum dots in a liquid-crystal-tunable microdisk resonator VL - 42 ER - TY - JOUR AB - GaAs-based semiconductor microdisks with high quality whispering gallery modes (Q44000) have been fabricated.A layer of self-organized InAs quantumdots (QDs) served as a light source to feed the optical modes at room temperature. In order to achieve frequency tuning of the optical modes, the microdisk devices have been immersed in 4 – cyano – 4´-pentylbiphenyl (5CB), a liquid crystal(LC) with a nematic phase below the clearing temperature of TC≈34°C .We have studied the device performance in the temperature rangeof T=20-50°C, in order to investigate the influence of the nematic–isotropic phase transition on the optical modes. Moreover,we havea pplied an AC electric field to the device,which leads in the nematic phase to a reorientation of the anisotropic dielectric tensor of the liquid crystal.This electrical anisotropy can be used to achieve electrical tunability of the optical modes.Using the finite-difference time domain (FDTD) technique with an anisotropic material model, we are able to describe the influence of the liquid crystal qualitatively. AU - Piegdon, Karoline A. AU - Offer, Matthias AU - Lorke, Axel AU - Urbanski, Martin AU - Hoischen, Andreas AU - Kitzerow, Heinz-Siegfried AU - Declair, Stefan AU - Förstner, Jens AU - Meier, Torsten AU - Reuter, Dirk AU - Wieck, Andreas D. AU - Meier, Cedrik ID - 4123 IS - 10 JF - Physica E: Low-dimensional Systems and Nanostructures KW - tet_topic_qd KW - tet_topic_microdisk SN - 1386-9477 TI - Self-assembled quantum dots in a liquid-crystal-tunable microdisk resonator VL - 42 ER - TY - JOUR AB - Very clean single photon emission from a single InGaAs/GaAs quantum dot is demonstrated by the use of a coherent optical state preparation. We present a concept for single photon emission, which uses p-shell Rabi-flopping followed by a sequence of relaxation and recombination. The proof of the (clean) single photon emission is performed by photon correlation measurements. AU - Ester, P. AU - Lackmann, L. AU - Hübner, M.C. AU - Michaelis de Vasconcellos, S. AU - Zrenner, Artur AU - Bichler, M. ID - 4556 IS - 6 JF - Physica E: Low-dimensional Systems and Nanostructures KW - Antibunching KW - Single photon emission KW - Rabi oscillation KW - Coherent manipulation SN - 1386-9477 TI - p-Shell Rabi-flopping and single photon emission in an InGaAs/GaAs quantum dot VL - 40 ER - TY - JOUR AU - Marquardt, Bastian AU - Russ, Marco AU - Lorke, Axel AU - Meier, Cedrik AU - Reuter, Dirk AU - Wieck, Andreas D. ID - 7641 IS - 6 JF - Physica E: Low-dimensional Systems and Nanostructures SN - 1386-9477 TI - Quantum dots as tunable scatterers for 2D- and 1D-electron systems VL - 40 ER - TY - JOUR AU - Grbić, B. AU - Leturcq, R. AU - Ihn, T. AU - Ensslin, K. AU - Reuter, Dirk AU - Wieck, A.D. ID - 8594 JF - Physica E: Low-dimensional Systems and Nanostructures SN - 1386-9477 TI - Strong spin–orbit interactions in carbon doped p-type GaAs heterostructures ER - TY - JOUR AU - Grbić, Boris AU - Leturcq, Renaud AU - Ihn, Thomas AU - Ensslin, Klaus AU - Reuter, Dirk AU - Wieck, Andreas D. ID - 8597 JF - Physica E: Low-dimensional Systems and Nanostructures SN - 1386-9477 TI - Aharonov–Bohm oscillations in p-type GaAs quantum rings ER - TY - JOUR AU - Notthoff, C. AU - Lorke, A. AU - Reuter, Dirk ID - 8598 JF - Physica E: Low-dimensional Systems and Nanostructures SN - 1386-9477 TI - High sensitivity far-infrared detection by resonant inter-Landau-level scattering ER -