DTI funding helps firms switch on OLED backlights
“The aim of the project is to develop a high efficiency white-light, thin, flexible, OLED solid state lighting system that will initially be geared towards the flat panel display market, in particular micro and flexible displays,” said OLED-T.
Based on work lead by company CTO Professor Poopathy Kathirgamanathan, OLED-T has developed various materials for OLED displays. As well as emissive compounds, it is working on electron and hole transport and injection layers, some of which it sells commercially.
“There is certainly a market for the materials that we are looking to develop. We are working closely with several backlight unit suppliers in the Far East and as such we are well placed to leverage the commercial benefits that will arise from our partnership with Microsharp, said OLED-T CEO Myrddin Jones. “The target for the end of the project is a backlight less than 1mm thick, and probably 3x3cm.”
Microsharp makes optical modification films including contrast-enhancement and optical matching layers. “We will be integrating the OLED on plastic; specifically on a micro-lens structure to increase intensity in the forward direction,” said Jones. For the emissive material, “a straight-forward answer would be combined red, green and blue colour sources. We need to achieve a good white”.
The firms will have to tackle the classic plastic substrate issues of thermal stability and ingress of oxygen and water.
“Deposition on a plastic substrate is not easy, as some materials need to be deposited at quite a high temperature. We will be looking to lay down seven or eight layers and then seal-on another plastic layer, all in a vacuum,” said Jones.
For the critical barrier layers and edge-sealing, OLED-T will work with materials from DuPont Teijin Films. Desiccants incorporated in the structure will “increase lifetime significantly”, said Jones, the target life for the project end-product is 5,000 hours.