Navigation Links
NREL and partners demonstrate quantum dots that assemble themselves

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
DOE/National Renewable Energy Laboratory

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:
(Date:11/25/2015)... ... November 25, 2015 , ... ... Organization of Black Aerospace Professionals (OPBAP) has been formalized with the signing of ... team leaders met with OPBAP leaders Capt. Karl Minter and Capt. Albert Glenn ...
(Date:11/25/2015)... Francisco, CA (PRWEB) , ... November 25, 2015 ... ... microbial genomics company uBiome, were featured on AngelList early in their initial angel ... launching an AngelList syndicate for individuals looking to make early stage investments in ...
(Date:11/24/2015)... 24, 2015 Cepheid (NASDAQ: CPHD ) ... the following conference, and invited investors to participate via ...      Tuesday, December 1, 2015 at 11.00 a.m. Eastern ...      Tuesday, December 1, 2015 at 11.00 a.m. Eastern ... New York, NY      Tuesday, December 1, ...
(Date:11/24/2015)... Mass. (PRWEB) , ... November 24, 2015 , ... ... to maintain healthy metabolism. But unless it is bound to proteins, copper is ... of Health (NIH), researchers at Worcester Polytechnic Institute (WPI) will conduct a systematic ...
Breaking Biology Technology:
(Date:10/29/2015)... 29, 2015  The J. Craig Venter Institute (JCVI) ... Synthesis and Biosecurity: Lessons Learned and Options for the ... and Human Services guidance for synthetic biology providers has ... --> --> Synthetic biology ... potential to pose unique biosecurity threats. It now is ...
(Date:10/29/2015)... , October 29, 2015 ... authentication company focused on the growing mobile commerce ... announces that StackCommerce, a leading marketplace to discover ... the Wocket® smart wallet on StackSocial for this ... ("NXT-ID" or the "Company"), a biometric authentication company ...
(Date:10/27/2015)... 27, 2015 Synaptics Inc. (NASDAQ: SYNA ), ... Google has adopted the Synaptics ® ClearPad ® ... power its newest flagship smartphones, the Nexus 5X by ... --> --> Synaptics works ... strategic collaboration in the joint development of next generation ...
Breaking Biology News(10 mins):