Navigation Links
NREL and partners demonstrate quantum dots that assemble themselves
Date:2/20/2013

Scientists from the U.S. Department of Energy's National Renewable Energy Laboratory and other labs have demonstrated a process whereby quantum dots can self-assemble at optimal locations in nanowires, a breakthrough that could improve solar cells, quantum computing, and lighting devices.

A paper on the new technology, "Self-assembled Quantum Dots in a Nanowire System for Quantum Photonics," appears in the current issue of the scientific journal Nature Materials.

Quantum dots are tiny crystals of semiconductor a few billionths of a meter in diameter. At that size they exhibit beneficial behaviors of quantum physics such as forming electron-hole pairs and harvesting excess energy.

The scientists demonstrated how quantum dots can self-assemble at the apex of the gallium arsenide/aluminum gallium arsenide core/shell nanowire interface. Crucially, the quantum dots, besides being highly stable, can be positioned precisely relative to the nanowire's center. That precision, combined with the materials' ability to provide quantum confinement for both the electrons and the holes, makes the approach a potential game-changer.

Electrons and holes typically locate in the lowest energy position within the confines of high-energy materials in the nanostructures. But in the new demonstration, the electron and hole, overlapping in a near-ideal way, are confined in the quantum dot itself at high energy rather than located at the lowest energy states. In this case, that's the gallium-arsenide core. It's like hitting the bulls-eye rather than the periphery.

The quantum dots, as a result, are very bright, spectrally narrow and highly anti-bunched, displaying excellent optical properties even when they are located just a few nanometers from the surface a feature that even surprised the scientists.

"Some Swiss scientists announced that they had achieved this, but scientists at the conference had a hard time believing it," said NREL senior scientist Jun-Wei Luo, one of the co-authors of the study. Luo got to work constructing a quantum-dot-in-nanowire system using NREL's supercomputer and was able to demonstrate that despite the fact that the overall band edges are formed by the gallium Arsenide core, the thin aluminum-rich barriers provide quantum confinement both for the electrons and the holes inside the aluminum-poor quantum dot. That explains the origin of the highly unusual optical transitions.

Several practical applications are possible. The fact that stable quantum dots can be placed very close to the surface of the nanometers raises a huge potential for their use in detecting local electric and magnetic fields. The quantum dots also could be used to charge converters for better light-harvesting, as in the case of photovoltaic cells.


'/>"/>

Contact: David Glickson
david.glickson@nrel.gov
303-275-4097
DOE/National Renewable Energy Laboratory
Source:Eurekalert

Related biology technology :

1. Organovo Partners With ZenBio to Create 3D Tissue Models
2. Transformation Dental Partners Launch Ground Breaking Cavity Prevention Program that Can Lower Tooth Decay Rates by 74%
3. Qualitas Health and Valicor Renewables Announce Strategic Partnership to Commercialize Algae-Based Omega-3 Supplements
4. Taylor-Wharton CryoScience 'Partners For Life' Awards Liquid Nitrogen Freezer to Comprehensive Cancer Center at University of Alabama at Birmingham
5. Tonicology LLC Partners with Taiwan's CGB, Corp. to Offer Pure Extracts of Rare Herbal Supplements
6. The Veterinary Bioscience Institute Partners with LabRoots to Produce Laboratory Animal Science BioConference Live
7. Touch Medical Media Splits From Touch Briefings, Launches a Series of Cutting Edge, Free to Access, Educational Resources and Signs an Updated Media Partnership With ECCO, The European CanCer Organisation Representing 60,000 Oncology Professionals
8. 5AM Solutions and LABVANTAGE Announce Partnership
9. GlycoCheck Announces Partnership in the United States with Vascular Health Sciences
10. Formedix Partners with Perceptive Informatics for Forthcoming Webcast, “Four Secrets to Using CDISC Standards to Enable Clinical Trial Efficiencies”
11. Wake Forest Innovations Partners with Veterinary Bioscience Institute to Develop Educational Programs for Life Science Professionals
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:2/10/2016)... Springfield, MO (PRWEB) , ... February 10, 2016 ... ... company, will attend the International Society of Pharmaceutical Engineering (ISPE) Rocky Mountain Chapter ... of ISPE is expecting to fill more than 100 tables for its annual ...
(Date:2/10/2016)... ... February 10, 2016 , ... Curoverse ... Azure. On Azure, Arvados provides capabilities for managing and processing genomic and health ... Azure from major institutions collecting and analyzing genomic data,” said Adam Berrey chief ...
(Date:2/9/2016)... ... February 09, 2016 , ... With a presidential election in ... Care Business Conference will bring together over 500 top healthcare leaders for a night ... transformation. The conference, organized by MBA students of the University of Pennsylvania’s Wharton School, ...
(Date:2/9/2016)... ... February 09, 2016 , ... Clinovo , the cloud-based ... Electronic Data Capture (EDC) system ClinCaptureand its new Contract Research Organization (CRO) Partner ... Conference in San Mateo, California on February 10th and 11th. Watch 2-min ...
Breaking Biology Technology:
(Date:2/9/2016)... Aware, Inc. (NASDAQ: AWRE ), a leading supplier ... fourth quarter and year ended December 31, 2015.  ... of 2015 was $6.9 million, an increase of 61% compared to ... the fourth quarter of 2015 was $2.6 million compared to $0.2 ... --> --> Higher revenue and operating income in ...
(Date:2/8/2016)... February 8, 2016 Worldcore ... which presents innovation for clients, comfort and unbeatable ... VoiceKey. --> Worldcore is the ... for clients, comfort and unbeatable security, with a ... Worldcore is the first EU-regulated ...
(Date:2/4/2016)... 2016 The field of Human Microbiome ... most popular hubs of the biotechnology industry. While ... studies of human microbiota, have garnered a lot ... microbiome space has literally exploded in terms of ... report focuses on biomedical aspects of research, development, ...
Breaking Biology News(10 mins):