Spatial carrier distribution in InP/GaAs type II quantum dots and quantum posts.
Summary of "Spatial carrier distribution in InP/GaAs type II quantum dots and quantum posts."
We performed a detailed investigation of the structural and optical properties of multi-layers of InP/GaAs quantum dots, which present a type II interface arrangement. Transmission electronic microscopy analysis has revealed relatively large dots that coalesce forming so-called quantum posts when the GaAs layer between the InP layers is thin. We observed that the structural properties and morphology affect the resulting radiative lifetime of the carriers in our systems. The carrier lifetimes are relatively long, as expected for type II systems, as compared to those observed for single layer InP/GaAs quantum dots. The interface intermixing effect has been pointed out as a limiting factor for obtaining an effective spatial separation of electrons and holes in the case of single layer InP/GaAs quantum-dot samples. In the present case this effect seems to be less critical due to the particular carrier wavefunction distribution along the structures.
Instituto de Física Gleb Wataghin, Unicamp, Campinas-SP, Brazil. firstname.lastname@example.org
This article was published in the following journal.
- PubMed Source: http://www.ncbi.nlm.nih.gov/pubmed/21212489
- DOI: http://dx.doi.org/10.1088/0957-4484/22/6/065703
Medical and Biotech [MESH] Definitions
Nanometer sized fragments (the dots) of semiconductor crystalline material which emit PHOTONS. The wavelength is based on the quantum confinement size of the dot. They are brighter and more persistent than organic chemical INDICATORS. They can be embedded in MICROBEADS for high throughput ANALYTICAL CHEMISTRY.
Nanometer-sized particles that are nanoscale in three dimensions. They include nanocrystaline materials; NANOCAPSULES; METAL NANOPARTICLES; DENDRIMERS, and QUANTUM DOTS. The uses of nanoparticles include DRUG DELIVERY SYSTEMS and cancer targeting and imaging.
The theory that the radiation and absorption of energy take place in definite quantities called quanta (E) which vary in size and are defined by the equation E=hv in which h is Planck's constant and v is the frequency of the radiation.
Discrete concentrations of energy, apparently massless elementary particles, that move at the speed of light. They are the unit or quantum of electromagnetic radiation. Photons are emitted when electrons move from one energy state to another. (From Hawley's Condensed Chemical Dictionary, 11th ed)
An enzyme of long-chain fatty acid synthesis, that adds a two-carbon unit from malonyl-(acyl carrier protein) to another molecule of fatty acyl-(acyl carrier protein), giving a beta-ketoacyl-(acyl carrier protein) with the release of carbon dioxide. EC 18.104.22.168.
We report electrically injected lasing in GaAs quantum dots (QDs) grown on GaAs(001) by droplet epitaxy. High-quality GaAs QDs with superior uniformity are formed using improved growth techniques invo...
We report on the effect of post-growth thermal annealing of -, [[Formula: see text]]-, and -oriented quantum dot chains grown by molecular beam epitaxy on GaAs(100) substrates patterned by U...
InAs quantum dot arrays are obtained on GaAs nanowire facets by molecular beam epitaxy. The GaAs nanowires are first grown by the gallium-assisted catalyst-free method. Decoration of the nanowire face...
Core/shell quantum dots (CdSe/Zns) conjugated with various nuclear localization signaling (NLS) peptides, which could facilitate the transportation of quantum dots across the plasma membrane into the...
We report on the effects of patterning and layering on multilayer InAs/GaAs(001) quantum dot structures laterally ordered using an in vacuo focused ion beam. The patterned hole size and lateral patte...
The purpose of the study is to evaluate the safety and efficacy of the composite Nail - the Quantum interlocking intramedullary nailing system in the reduction of humeral fractures.
Background: The therapy with pulsed electromagnetic fields (PEFs) has been used as a therapeutic modality for at least 40 years. However, their effect in the migraine prophylaxis is unclea...
This study will test the effectiveness of two different tuberculosis (TB) prevention strategies, DOTS or DOTS-A. DOTS is the current prevention strategy for TB. DOTS-A is an enhanced preve...
The lack of blood flow to the small intestine causes mesenteric ischemia. Using a Superconducting QUantum Interference Device (SQUID) which measures the magnetic field of the small intest...
The lack of blood flow to the small intestine causes mesenteric ischemia. Using a Superconducting QUantum Interference Device (SQUID) which measures the magnetic field of the small intesti...