Among the patents now allowed in the US is a patent relating to OLEDs which comprise hole transport, electron transport and emissive components, using type II interfaces, contained in the same molecule. This is believed to be of considerable importance in the context of the printing of OLED devices. Molecules containing 'type II' interfaces are believed to be important in achieving high efficiency display devices.
Other new US patents allowed include a patent relating to the use of a dielectric barrier layer over the key emissive layer to protect it from damage due to sputtering of a conductive layer. This is expected to have important application in top emitting devices in which the light does not have to pass between the transistors but, more efficiently, through a transparent cathode structure.
Another allowed patent is jointly owned with Seiko Epson Corporation and covers certain solvents used in ink formulations for ink jet printing of polymer OLEDs.
