University of California scientists working at Los Alamos National Laboratory with a colleague from Sandia National Laboratories have developed a new method for exciting light emission from nanocrystal quantum dots. The discovery provides a way to supply energy to quantum dots without wires, and paves the way for a potentially wider use of tunable nanocrystalline materials in a variety of novel light-emitting technologies ranging from electronic displays to solid-state lighting and electrically pumped nanoscale lasers.
In a paper published in the todays issue of the scientific journal Nature, Los Alamos Chemistry Division scientist Victor Klimov and his colleagues describe their method for using non-contact, non-radiative energy transfer from a quantum well to produce light from an adjacent layer of nanocrystals. A quantum well is a semiconductor structure in which an electron is sandwiched between two barriers so that its motion is confined to two dimensions. In a real-life device, the quantum well would be pumped electrically in the same way a common quantum-well light-emitting diode is pumped.
According to Klimov, "The transfer of energy is fast enough to compete with exciton recombination in the quantum well, and that allows us to "move" more than 50 percent of the excitons to adjacent quantum dots. The recombination of these transferred excitons leads to emission of light with color that can be controlled by quantum dot size. The high efficiency of energy transfer in combination with the exceptional luminescent properties of nanocrystal quantum dots make hybrid quantum-well/nanocrystal devices feasible as efficient sources of any color light -- or even white light."
Todd Hanson | LANL
Agricultural insecticide contamination threatens U.S. surface water integrity at the national scale
06.12.2018 | Universität Koblenz-Landau
Improving hydropower through long-range drought forecasts
06.12.2018 | Schweizerischer Nationalfonds SNF
A widely used diabetes medication combined with an antihypertensive drug specifically inhibits tumor growth – this was discovered by researchers from the University of Basel’s Biozentrum two years ago. In a follow-up study, recently published in “Cell Reports”, the scientists report that this drug cocktail induces cancer cell death by switching off their energy supply.
The widely used anti-diabetes drug metformin not only reduces blood sugar but also has an anti-cancer effect. However, the metformin dose commonly used in the...
A research team from the University of Zurich has developed a new drone that can retract its propeller arms in flight and make itself small to fit through narrow gaps and holes. This is particularly useful when searching for victims of natural disasters.
Inspecting a damaged building after an earthquake or during a fire is exactly the kind of job that human rescuers would like drones to do for them. A flying...
Over the last decade, there has been much excitement about the discovery, recognised by the Nobel Prize in Physics only two years ago, that there are two types...
What if a sensor sensing a thing could be part of the thing itself? Rice University engineers believe they have a two-dimensional solution to do just that.
Rice engineers led by materials scientists Pulickel Ajayan and Jun Lou have developed a method to make atom-flat sensors that seamlessly integrate with devices...
Scientists at the University of Stuttgart and the Karlsruhe Institute of Technology (KIT) succeed in important further development on the way to quantum Computers.
Quantum computers one day should be able to solve certain computing problems much faster than a classical computer. One of the most promising approaches is...
12.12.2018 | Event News
10.12.2018 | Event News
06.12.2018 | Event News
12.12.2018 | Health and Medicine
12.12.2018 | Physics and Astronomy
12.12.2018 | Health and Medicine