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:1/19/2017)... N.J. , Jan. 18, 2017 BD (Becton, Dickinson ... company, announced today that it will host a live webcast of ... 1 p.m. (ET). The webcast can be accessed ... available for replay through Tuesday, January 31, 2017. ... About BD BD is ...
(Date:1/18/2017)... , Jan. 18, 2017 Applied ... mechanistic modeling to drug research and development, today ... Co-Founder, President, and CEO of Applied BioMath, will ... Informatics and Modeling (BAGIM) Meeting on Thursday January ... Cambridge , MA.   Dr. Burke,s talk ...
(Date:1/18/2017)... ... January 18, 2017 , ... Whitehouse Labs ... Within Albany Molecular Research, Inc. (AMRI), the scientific staff dedicated to Extractables / ... planned for further growth in 2017. Extractable & Leachable evaluations have become increasingly ...
(Date:1/18/2017)... OF PRUSSIA, PA (PRWEB) , ... January 18, ... ... disrupt clinical operations again at the CHI SCOPE Summit for Clinical Ops Executives ... AstraZeneca in engaging panel discussions to examine vital clinical research issues such as ...
Breaking Biology Technology:
(Date:1/4/2017)... -- For the thousands of attendees at this year,s International Consumer Electronics Show ... biometric measurement devices and services, will be featuring its new line of ... Medical,s special CES Exhibit Suite , the new upper arm and ... WellnessConnected product platform.  Continue ... ...
(Date:12/22/2016)... , Dec. 20, 2016  As part of its longstanding ... leading personal genetics company, recently released its latest children,s book, ... The book focuses on the topics of inheritance and variation ... Standards (NGSS) taught in elementary school classrooms in the US. ... series by illustrator Ariana Killoran , whose previous book ...
(Date:12/20/2016)... and GENEVA, Dec, 20, 2016   ... data sensor technology, and STMicroelectronics (NYSE: ... spectrum of electronics applications, announced today the launch ... kit for biometric wearables that includes ST,s compact ... Valencell,s Benchmark™ biometric sensor system. Together, ...
Breaking Biology News(10 mins):