Search results for "Self assemble"

Size dependent carrier thermal escape and transfer in bimodally distributed self assembled InAs/GaAs quantum dots

2012

We have investigated the temperature dependent recombination dynamics in two bimodally distributed InAs self assembled quantum dots samples. A rate equations model has been implemented to investigate the thermally activated carrier escape mechanism which changes from exciton-like to uncorrelated electron and hole pairs as the quantum dot size varies. For the smaller dots, we find a hot exciton thermal escape process. We evaluated the thermal transfer process between quantum dots by the quantum dot density and carrier escape properties of both samples. © 2012 American Institute of Physics.

Halogen bond directionality translates tecton geometry into self-assembled architecture geometry

2013

The structures of halogen-bonded infinite chains involving two diiodoperfluoroalkanes and a bent bis(pyrid-4′-yl)oxadiazole show that the geometry of the pyridyl pendant rings is translated into the angle between the formed halogen bonds.

Self-Assembled Hydrogen-Bonded Dimeric Capsules with High Kinetic Stability

2000

Oscillator strength reduction induced by external electric fields in self-assembled quantum dots and rings

2007

We have carried out continuous wave and time resolved photoluminescence experiments in self-assembled In(Ga)As quantum dots and quantum rings embedded in field effect structure devices. In both kinds of nanostructures, we find a noticeable increase of the exciton radiative lifetime with the external voltage bias that must be attributed to the field-induced polarizability of the confined electron hole pair. The interplay between the exciton radiative recombination and the electronic carrier tunneling in the presence of a stationary electric field is therefore investigated and compared with a numerical calculation based on the effective mass approximation.

Tuneable Emission of Polyhedral Oligomeric Silsesquioxane Based Nanostructures that Self-Assemble in the Presence of Europium(III) Ions: Reversible t…

2020

[EN] Hybrid nanostructures with switchable and reversible "blue-red-green" emission were efficiently synthesized. These nanostructures comprise polyhedral oligomeric silsesquioxanes (POSS) that behave as a nanocage that can be functionalized with terpyridine-based organic ligands, which can be easily complexed with europium (III) ions. The complexes were characterized by UV-Vis and fluorescence spectroscopy and their stoichiometry was also confirmed by H-1 NMR spectroscopy. In the presence of the Eu(III) ions, the octafunctionalized nanocages self-assemble to form 3D architectures that display an intense red-emission, especially in the solid state. The presence of an alkenyl group bridging …

Self-Assembled Zinc Oxide Quantum Dots Using Spray Pyrolysis Methodology

2011

Self-assembled ZnO quantum dots (QDs) have been obtained on different substrates by using the atmospheric spray pyrolysis methodology under well-defined growth conditions. The evolution of size and...

Self-Assembled Hydrogen Bonded Dimers of Calix[4]arenes

1998

Self-assembly of suitably functionalized molecules to well defined supramolecular structures has become a topic of current interest. Various molecules have been designed which are able to mimic in part the recognition and self-organisation processes which are found as a general principle in nature.[1]

Size self-filtering effect in vertical stacks of InAs/InP self-assembled quantum wires

2003

3 páginas, 2 figuras.-- PACS: 73.21.Hb; 78.55.Cr; 78.67.Lt.-- Proceedings of the International Conference on Superlattices, Nano-structures and Nano-devices ICSNN 2002.

Self-assembled FeCo/gelatin nanospheres with rapid magnetic response and high biomolecule-loading capacity.

2009

Self-assembled metal-oxide nanoparticles on GaAs: infrared absorption enabled by localized surface plasmons

2021

Abstract Metal-oxides hold promise as superior plasmonic materials in the mid-infrared compared to metals, although their integration over established material technologies still remains challenging. We demonstrate localized surface plasmons in self-assembled, hemispherical CdZnO metal-oxide nanoparticles on GaAs, as a route to enhance the absorption in mid-infrared photodetectors. In this system, two localized surface plasmon modes are identified at 5.3 and 2.7 μm, which yield an enhancement of the light intensity in the underlying GaAs. In the case of the long-wavelength mode the enhancement is as large as 100 near the interface, and persists at depths down to 50 nm. We show numerically t…