Integration of organic light-emitting diode and organic transistor via a tandem structure

A high-performance organic active matrix pixel was fabricated by using a metal oxide (V2O5) coupling layer that effectively integrates an organic light-emitting diode (OLED) on top of an organic field-effect transistor (OFET). The field-effect mobility of the OFET approached 0.5 cm(2) V-1 s(-1) and the ON/OFF current ratio was > 10(3). The brightness of the OLED was on the order of 2000 cd/m(2), with an efficiency above 3.3 cd/A. The present work describes in detail a methodology for sizing and stacking an OFET in bottom-emitting active matrix pixel circuits. The confinement of pixel dimension ensures the uniformity of light emission. The material for coupling layer can be tailored to achieve maximum device efficiency. A unique active matrix pixel circuit is proposed that renders both the OFET and OLED their individual performance after integration. (c) 2005 American Institute of Physics.