A research team used a new generation of engineered quantum dots to improve quality of quantum dot light emitting diodes (QD-LED) displays. This development can further the technology for future HDTVs.
QD-LED is another display technology which is still on its development stage. Its structure is somehow similar to organic light-emitting diode (OLED) but is different in terms of the light source. The light source of a QD-LED comes from cadmium selenide (CdSe) nanocrystals, or quantum dots. OLED technology is an improvement from LED and most of the smartphones and tablets now have OLED displays. Samsung and LG TVs are also equipped with OLED displays. If QD-LED becomes successfully developed, its display quality will be so much better than its predecessor especially on pure color quality.
"QD-LEDs can potentially provide many advantages over standard lighting technologies, such as incandescent bulbs, especially in the areas of efficiency, operating lifetime and the color quality of the emitted light," said Victor Klimov, a scientist from the Los Alamos National Laboratory (LANL) in a statement. He is also leader of the Nanotechnology and Advanced Spectroscopy team working on the QD-LED technology.
Research of QD-LED technology had shown impressive outcomes and it may not be long before it can be offered for commercial use. The researchers are able to make it spectrally narrow with tunable emission and easier to produce. The only problem that is still pending is the so-called “droop” in its efficiency.
A “droop” is the inability of a system to maintain a stable electricity generation which may cause lagging due to speed error or mismatch. Having a droop on displays may result to unstable brightness.
The researchers found a way to control the droop on QD-LEDs and have identified the main problem—the Auger effect. This process recombines the electron and a hole and emits the energy as heat instead of photons.
The team to engineered the quantum dots by over coating each quantum dot with cadmium sulfide. The method helped lessen the impact of Auger effect and balance the flow of the electrons.
"This fine tuning of electron and hole injection currents helps maintain the dots in a charge-neutral state and thus prevents activation of Auger recombination," said Jeffrey Pietryga, a chemist in the nanotech team.
The study was published in the Oct. 25 issue of Nature Communications.