QDs Generate Light for Next-Generation Displays (2
Post# of 22456
Such precise, tunable color allows display makers to accurately adjust the display gamut area and overlap with a specific standard (e.g., NTSC or Adobe RGB) while keeping system efficiency as high as possible. This is critical, because displays and panels of various sizes made by different manufacturers can have dissimilar CFAs, light-management architectures and materials that greatly influence how much light and which wavelengths from the BLU make it through the panel to the viewer.
Material efficiency: QDs vs. phosphors
Separately engineering the semiconductor core, shell and ligand composition using colloidal chemistry maximizes the efficiency of QD materials in the solid state and increases their efficiency at temperatures and fluxes relevant to LCD displays. Using a CdSe core and a shell made up of Cd, Zn and S, we have achieved solid-state emission efficiencies (external quantum efficiency, or EQE) of >95 percent in the red and green wavelength regions at scale. In addition, we have directly addressed temperature stability of the emission efficiency by focusing on QD exciton confinement and maximizing the conduction and valence band offsets of the shell band energies relative to core band energies.
Advancing the QD shell synthesis process results in QD materials that can maintain solid-state efficiencies of >95 percent at temperatures as high as 150 °C.
http://www.photonics.com/Article.aspx?AID=56627
......160 C to 260 C, .....QDX tm a step beyond, lol
High-efficiency light-emitting devices based on quantum dots with tailored nanostructures
We report a full series of blue, green and red quantum-dot-based light-emitting devices (QD-LEDs), all with high external quantum efficiencies over 10%. We show that the fine nanostructure of quantum dots—especially the composition of the graded intermediate shell and the thickness of the outer shell—plays a very important role in determining QD-LED device performance due to its effects on charge injection, transport and recombination. These simple devices have maximum current and external quantum efficiencies of 63 cd A−1 and 14.5% for green QD-LEDs, 15 cd A−1 and 12.0% for red devices, and 4.4 cd A−1 and 10.7% for blue devices, all of which are well maintained over a wide range of luminances from 102 to 104 cd m−2. All the QD-LEDs are solution-processed for ease of mass production, and have low turn-on voltages and saturated pure colours. The green and red devices exhibit lifetimes of more than 90,000 and 300,000 h, respectively.
http://www.nature.com/nphoton/journal/v9/n4/f...15.36.html