Quantum dots in displays: the story so far
The primary market of QDs today, beyond research uses, is in displays, Here, the driver is achieving wide color gamut displays thanks to the ultra-narrowband emission of QDs. This attribute is helping position LCDs as a viable competitor against large-sized premium-priced high color quality OLED displays.
Up to now, the QDs’ material characteristics have defined their use case. The QDs have been essentially only integrated into displays as ‘remote’ phosphors. In one implementation, the QDs are loaded into a resin which is then coated onto a film that is then sandwiched by two barrier (encapsulation) layers. This arrangement is called film-type QD or QD enhancement film (QDEF). In the other implementation, the QDs are put into tubes which are placed at the edge of displays. This is generally called Edge Optic QDs
In both cases, QDs re-emit the light form the phosphor converted backlight LEDs and in doing so narrow the emission spectrum, thus achieving wide colour gamut and thus pushing the display industry further towards the Rec2020 standard. In both cases, ‘remote’ phosphor integration was adopted because QDs could not tolerate harsher heat or light flux stress conditions which a closer proximity to the light source (LED) would have imposed upon them.
The edge optic QD implementation is now essentially obsolete. Its main proponent (QD Vision) lost an IP battle against the market leader (Nanosys), and consequently had to sell its patent portfolio at a bargain price to a leading QD user (Samsung). The film-type QD implementation however is continuing its growth.