Recently, researchers at Koc University in Istanbul, Turkey, produced relatively efficient LED using quantum dots suspended in liquid. The researchers point out that when quantum dots are removed from liquid and fixed into solid form, the emission efficiency of quantum dots will be reduced.
This loss of efficiency is called the matrix material effect. Therefore, researchers only need to integrate liquid into LED to eliminate matrix effect. The luminous efficiency of RGB and GB white light can reach 64 LM / W and 105 LM / W.
According to their theoretical calculations, the luminous efficiency of liquid QD-LED can reach 200 LM / W. The researchers also pointed out that the optical properties of the fluid medium could be changed by replacing the medium, and the spectra could be modified by controlling the mixture ratio of the fluid.
They show that the liquid based quantum dots can increase the luminous efficiency by more than 50% due to the inhibition of the matrix material effect. Secondly, with the increase of quantum yield, the number of emitted photons is significantly higher than the number of absorbed photons, which leads to more efficient color conversion and higher white light LED efficiency.
They also fine tuned the color conversion spectrum to bring the peak closer to the peak of the sensitivity function. This additional fine tuning results in the high luminous efficiency of light radiation.
Researchers have published the findings in the Journal of Optical Society Optica.