Apr 3, 2017: Researchers from Skolkovo Institute of Science and Technology Skoltech, Russia along with scientist from the UK and Taiwan have come up with a new photonic white light-emitting diode (LED) structure with unparalleled efficiency parameters. This new technology has paved way for ultra-thin and reasonable LEDs.
Dr. Mael Brossard, one of the head researchers said that compared to other contemporary emitters, it is much simpler to add the recently designed structures into the usual LED screens, thus helping to reduce the overall costs.
Furthermore, this new technology facilitates for additional control on the directionality of the light release, which is vigorously more useful. Such features help in making the development extremely appealing to the lighting business, added Brossard.
New technology opens route for ultra-thin and cheap LEDs
The regular white LEDs are based on a semiconductor gallium nitrate GaN, which releases the light in ultraviolet and blue areas once it gets activated with the electric current. Next, the photons released get absorbed by other materials and then reemission of the light in a more extensive wave range creating a white spectrum takes place.
Quatum dots for applications
Such substances that are competent of converting absorbed energy to the perceptible light are known as luminophores. Of late, quantum dots have been recommended for applications like luminophores since the QDs irradiation parameters can be tuned in an easy manner.
But, in the initial prototypical white LEDs, the luminophore has been deposited as a different layer above the blue LED comprised of GaN, which has strongly restricted the efficiency of the entire device.
In this study, the researchers have suggested the novel hybrid structure where the QDs will get encapsulated in the blue LED layer in an episodic manner. This move increases the quantum yield which refers to the ratio between the number of lights released and absorbed photons along with other descriptions of the device.
Brossard said that the brilliant coupling between the QD emitters and blue emission from GaN LED paves way for unparalleled color conversion and helpful quantum yield which is a crucial metric for white light LEDs.
This facilitates to avoid the encapsulation completely in the epoxy layer that normally consists of white phosphors to get ultra-thin LED devices, Brossard added.