Phase separation of conjugated polymers — tools for new functions in polymer leds

Within the single family of substituted poly(thiophenes) it is possible to realize such diverse device designs as voltage controlled colours from polymer LEDs, sub-micron size LEDs, and white light emitters. Many of these features become possible by the use of polymer blends in which one or more poly(thiophenes) are mixed with a matrix polymer (PMMA). The phase structure in these blends can be controlled by stoichiometry and mode of formation. That phase structure can be used to prevent exciton transfer, and to define new colours in polymer LEDs. It also allows us to make anisotropic conductors suitable for contacting optical devices.