What They Say
Toshiba has a new phosphor that is said to have excellent colour purity and luminence that is six times better than current phosphors when driven by UV light. There are applications in a range of uses but one is in microLED. Toshiba said:
Toshiba has focused its photoluminescence research on novel lanthanide luminescent complexes. The company has developed a proprietary molecular design method, and used this to bind the ions of a standard Eu(III) luminescent complex with two or more phosphine oxide structures, including a branched tetraphosphine tetraoxide ligand recently discovered by Toshiba (Figure 2). This created a new structure that is highly soluble, with excellent transparency, and that successfully increases luminescence intensity to achieve high colour purity and durable emission. The molecular design method also has the potential to create phosphors that emit different colored light when applied to different luminescent complexes. (Figure 3)
Details will be presented at IDW.
What We Think
This is interesting, indeed. The chemistry is a bit above my pay grade, but a claim of a boost in efficiency of 6X is significant. As we have reported before, there are a number of firms working on QD displays that use UV including Applied Materials. Blue has been a particular challenge but we reported some interesting work from Japan last week (Bottom Up, ‘Cinematic’ Chemistry for Blue QDs). The last year or two have really seemed to have seen a significant boost in material capabilities. (BR)
Figure 2: Eu(III) complexes with two or more different phosphine oxide structures realised by Toshiba’s molecular design method.
Figure 3: The molecular design method has the potential to create phosphors that emit different colored light when applied to different luminescent complexes.
Specifications of the new phosphor
| Appearance | Milky white powder |
| Excitation spectrum | Deep ultraviolet (222 nm) to purple (405 nm) |
| Emission spectrum | 613 nm (red) |
| Resin solubility | 1×10-3 mol/l in ethyl acetate and hexane |
