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Structures with self-organised InAs quantum dots in a GaAs matrix were grown by the low pressure metal-organic vapour phase epitaxy (LP-MOVPE) technique. Photoluminescence in combination with photomodulated reflectance spectroscopy were…

Materials Science · Physics 2007-08-13 P. Hazdra , J. Voves , J. Oswald , K. Kuldova , A. Hospodkova , E. Hulicius , J. Pangrac

Integrating light emitters based on III-V materials with silicon-based electronics is crucial for further increase in data transfer rates in communication systems since the indirect bandgap of silicon prevents its direct use as a light…

In the present work, we were able to identify and characterize a new source of in-plane optical anisotropies (IOAs) occurring in asymmetric DQWs; namely a reduction of the symmetry from $D_{2d}$ to $C_{2v}$ as imposed by asymmetry along the…

A transition from a cylindrical quantum dot to a highly elongated quantum dash is theoretically studied here with an atomistic approach combining empirical tight binding for single particle states and configuration interaction method for…

Mesoscale and Nanoscale Physics · Physics 2019-05-08 Michał Zieliński

In the recent work of Ref.\cite{Vlaic2017-bs}, it has been shown that Pb nanocrystals grown on the electron accumulation layer at the (110) surface of InAs are in the regime of Coulomb blockade. This enabled the first scanning tunneling…

In this paper, we have investigated the optical properties of GaAs nanocone (NC), inverted nanocone (INC), and hourglass (HG) shaped solar cells by performing Finite Difference Time Domain (FDTD) simulations. The different structures are…

Optics · Physics 2022-08-19 Sambuddha Majumder , Sooraj Ravindran

We report on stacked multiple quantum dots (QDs) formed inside inverted pyramidal recesses, which allow for the precise positioning of the QDs themselves. Specifically we fabricated double QDs with varying inter-dot distance and ensembles…

Mesoscale and Nanoscale Physics · Physics 2017-09-01 S. T. Moroni , T. H. Chung , G. Juska , A. Gocalinska , E. Pelucchi

A concept for the fabrication of highly symmetric quantum dots that are coherently embedded in a single crystalline matrix is demonstrated. In this approach, the formation of the quantum dots is induced by a transformation of an epitaxial…

Materials Science · Physics 2009-11-11 W. Heiss , H. Groiss , E. Kaufmann , G. Hesser , M. Boberl , G. Springholz , F. Schaffler , K. Koike , H. Harada , M. Yano

We investigate the properties of electronic states and optical transitions in hexagonal GaAs quantum dots within AlGaAs nanowires. Such dots are particularly interesting due to their high degree of symmetry. A streamlined postsymmetrization…

Mesoscale and Nanoscale Physics · Physics 2015-11-18 Guro K. Svendsen , Johannes Skaar , Helge Weman , Marc-André Dupertuis

We present a model for the interplay between the fundamental phenomena responsible for the formation of nanostructures by metalorganic vapour phase epitaxy on patterned (001)/(111)B GaAs substrates. Experiments have demonstrated that…

Materials Science · Physics 2015-05-30 E. Pelucchi , V. Dimastrodonato , A. Rudra , K. Leifer , E. Kapon , L. Bethke , P. Zestanakis , D. D. Vvedensky

The demonstration of isotropic polarization response from semiconductor quantum dots (QDs) is a crucial step towards the design of several optoelectronic technologies. Among many parameters that impact the degree of polarization (DOP) of a…

Mesoscale and Nanoscale Physics · Physics 2012-10-09 Muhammad Usman

A systematic study of the impact of annealing on the electronic properties of single InAs/GaAs quantum dots (QDs) is presented. Single QD cathodoluminescence spectra are recorded to trace the evolution of one and the same QD over several…

We present an inverted GaAs 2D electron gas with self-assembled InAs quantum dots in close proximity, with the goal of combining quantum transport with quantum optics experiments. We have grown and characterized several wafers -- using…

Mesoscale and Nanoscale Physics · Physics 2014-04-03 F. Dettwiler , P. Fallahi , D. Scholz , E. Reiger , D. Schuh , A. Badolato , W. Wegscheider , D. M. Zumbühl

We report on photoluminescence measurements of vertically stacked InAs/GaAs quantum dots grown by molecular-beam epitaxy on focused ion beam patterned hole arrays with varying array spacing. Quantum dot emission at 1.24 eV was observed only…

Materials Science · Physics 2011-01-14 T. W. Saucer , J. -E. Lee , A. J. Martin , D. Tien , J. M. Millunchick , V. Sih

We show that fully self-assembled optically-active quantum dots (QDs) embedded in MBE-grown GaAs/AlGaAs core-shell nanowires (NWs) are coupled to the NW mechanical motion. Oscillations of the NW modulate the QD emission energy in a broad…

Mesoscale and Nanoscale Physics · Physics 2014-08-22 M. Montinaro , G. Wüst , M. Munsch , Y. Fontana , E. Russo-Averchi , M. Heiss , A. Fontcuberta i Morral , R. J. Warburton , M. Poggio

Tailoring electronic and optical properties of self-assembled InAs quantum dots (QDs) is a critical limit for the design of several QD-based optoelectronic devices operating in the telecom frequency range. We describe how a fine control of…

Mesoscale and Nanoscale Physics · Physics 2015-06-18 Vittorianna Tasco , Muhammad Usman , Milena De Giorgi , Adriana Passaseo

We present self-assembly of InAs/InAlAs quantum dots by droplet epitaxy technique on vicinal GaAs(111)A substrates. The small miscut angle, while maintaining the symmetries imposed to the quantum dot from the surface, allows fast growth…

Semiconductor coupled quantum dots provide a unique opportunity of tuning bandgaps by tailoring band offsets, making them ideal for photovoltaic and other applications. Here, we have studied stability, trends in the band gap, band offsets,…

Mesoscale and Nanoscale Physics · Physics 2022-08-16 Arup Chakraborty , Bidisa Das , Indra Dasgupta

High-quality InAs quantum wells grown on InP are a promising platform for topological quantum information processing due to their large g-factor, strong Rashba spin-orbit interaction, and their compatibility with in-situ-deposited…

Materials Science · Physics 2026-03-10 Zijin Lei , Yuze Wu , Christian Reichl , Stefan Fält , Werner Wegscheider

The electronic structure of InAs quantum dots covered with the GaAs(1-y)Sb(y) strain reducing layer has been studied using the k.p theory. We explain previous experimental observations of the red shift of the photoluminescence emission with…

Mesoscale and Nanoscale Physics · Physics 2012-09-28 P. Klenovský , V. Křápek , D. Munzar , J. Humlíček