Molecularly doped polymeric network nanolayers for organic light-emitting devices

Abstract

For a couple of decades a keen interest has been paid to organic light-emitting devices (OLED) that utilize organic semiconductors (small molecules or polymers) as an electrooptical medium.^1–3 Recently the device efficiency issue, which was one of the crucial points for low power consumption displays in portable electronic applications, has been almost sorted out by making use of triplet emissions.⁴ However, the commercialization of OLED is still awkward and very limited to a small size display because the device reliability (lifetime) lags behind the criteria of consumer electronics, even though it has been improved by device engineering such as accelerated pre-oxidation method (APOM).⁵ This teaches us a concrete lesson that enhancing device reliability depends critically on the intrinsic property of organic semiconductor materials which includes chemical, physical, and thermal stabilities. In this regard, we have extensively studied thermally stable polymers and hybrid composite systems.^6–8