Patterning-free integration of polymer light-emitting diode and polymer transistor

We demonstrate an integration of polymer light-emitting diode (LED) and polymer transistor in which no patterning of the organic layers is needed. Intrinsic high-mobility semiconducting conjugated polymer poly(3-hexylthiophene)(P3HT) is used as the hole-transport layer for polymer LED. The light emission efficiency is only slightly lower than the LED with conventional heavily doped hole-transport layer. Such LED is easily integrated with a P3HT transistor without patterning.