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We study the luminescence dynamics of telecom wavelength InAs quantum dots grown on InP(111)A by droplet epitaxy. The use of the ternary alloy InAlGaAs as a barrier material leads to photon emission in the 1.55 $\mu$m telecom C-band. The…

Mesoscale and Nanoscale Physics · Physics 2020-02-05 N. Ha , T. Mano , S. Dubos , T. Kuroda , Y. Sakuma , K. Sakoda

Time-resolved microphotoluminescence study is presented for quantum dots which are formed in the InAs/GaAs wetting layer. These dots are due to fluctuations of In composition in the wetting layer. They show spectrally sharp luminescence…

Mesoscale and Nanoscale Physics · Physics 2011-09-27 T. Kazimierczuk , A. Golnik , P. Kossacki , J. Gaj , Z. Wasilewski , A. Babinski

We report on the observation of photoluminescence from positive, neutral and negative charge states of single semiconductor quantum dots. For this purpose we designed a structure enabling optical injection of a controlled unequal number of…

We explore the dynamics and directionality of spontaneous emission from self-assembled In(Ga)As quantum dots into TE-polarised guided modes in GaAs two-dimensional photonic crystal waveguides. The local group velocity of the guided…

GaN/AlxGa1-xN quantum wells were grown by molecular beam epitaxy on high quality bulk (0001) GaN substrates. The quantum well thickness was set in the 6-8 nm range to favor the photoluminescence emission of indirect excitons. Indeed, such…

The photoluminescence (PL) spectra of a two-dimensional electron system induced in a Be-delta-doped GaAs/AlGaAs quantum well (QW) with a back gate are measured. The electron density is controlled from 1 X 10^{9} cm^{-2} to 2.5 X 10^{11}…

Mesoscale and Nanoscale Physics · Physics 2009-11-10 M. Yamaguchi , S. Nomura , D. Sato , T. Akazaki , H. Tamura , H. Takayanagi

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…

InAs semiconductor quantum dots (QDs) emitting in the near infrared are promising platforms for on-demand single-photon sources and spin-photon interfaces. However, the realization of quantum-photonic nanodevices emitting in the second and…

The development of deterministic single photon sources emitting in the telecommunication bands is a key challenge for quantum communication and photonic quantum computing. Here, we investigate the optical properties and single-photon…

Mesoscale and Nanoscale Physics · Physics 2025-05-30 Beatrice Costa , Bianca Scaparra , Xiao Wei , Hubert Riedl , Gregor Koblmüller , Eugenio Zallo , Jonathan Finley , Lukas Hanschke , Kai Müller

We observe experimentally that ensembles of quantum dots in three-dimensional (3D) photonic crystals reveal strongly nonexponential time-resolved emission. These complex emission decay curves are analyzed with a continuous distribution of…

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

The design of some optical devices such as semiconductor optical amplifiers for telecommunication applications requires polarization-insensitive optical emission at the long wavelengths (1300-1550 nm). Self-assembled InAs/GaAs quantum dots…

Materials Science · Physics 2015-05-20 Muhammad Usman , Susannah Heck , Edmund Clarke , Peter Spencer , Hoon Ryu , Ray Murray , Gerhard Klimeck

We have developed a scanning photoluminescence technique that can directly map out the local two-dimensional electron density with a relative accuracy of $\sim2.2\times10^8$ cm$^{-2}$. The validity of this approach is confirmed by the…

Optical properties of large arrays of isolated quantum dots are discussed in order to interpret the existent photoluminescence data. The presented theory explains the large observed shift between the lowest emission and absorption energies…

Condensed Matter · Physics 2009-10-28 E. V. Tsiper

Room temperature photoluminescence and optical absorption spectra have been measured in wurtzite In$_{x}$Al$_{y}$Ga$_{1-x-y}$N (x $\approx$ 0.06, 0.02 < y < 0.27) layers grown by molecular beam epitaxy. Photoluminescence spectra show both…

We fabricated GaAs/AlGaAs quantum dots by droplet epitaxy method, and obtained the geometries of the dots from scanning transmission electron microscopy data. Post-thermal annealing is essential for the optical activation of quantum dots…

Materials Science · Physics 2012-11-15 Pilkyung Moon , J. D. Lee , S. K. Ha , E. H. Lee , W. J. Choi , J. D. Song , J. S. Kim , L. S. Dang

Due to their band-structure and optical properties, InAs/InP quantum dots (QDs) constitute a promising system for single-photon generation at third telecom window of silica fibers and for applications in quantum communication networks.…

Mesoscale and Nanoscale Physics · Physics 2020-05-20 P. Holewa , M. Gawełczyk , C. Ciostek , P. Wyborski , S. Kadkhodazadeh , E. Semenova , M. Syperek

In this paper, we demonstrate the infrared photoluminescence emission from Ge(Si) quantum dots enhanced with collective Mie modes of silicon nanopillars. We show that the excitation of band edge dipolar modes of a linear nanopillar array…

We report on enhanced fluorescence of lead sulfide quantum dots interacting with leaky modes of slab-type silicon photonic crystals. The photonic crystal slabs were fabricated supporting leaky modes in the near infrared wavelength range.…

Optics · Physics 2017-08-23 C. Barth , S. Roder , D. Brodoceanu , T. Kraus , M. Hammerschmidt , S. Burger , C. Becker

We report optical orientation experiments in individual, strain free GaAs quantum dots in AlGaAs grown by droplet epitaxy. Circularly polarized optical excitation yields strong circular polarization of the resulting photoluminescence at 4K.…