Improved efficiency in solution processed green phosphorescent organic light-emitting diodes using a double layer emitting structure fabricated by a stamp transfer printing process

A high efficiency soluble green phosphorescent organic light-emitting diode (PHOLED) was developed using a double layer emitting structure fabricated by a stamp transfer printing process. One green emitting layer with a hole transport type host material was coated on a hole transport layer and the other green emitting layer with an electron transport type host material was stamp transfer printed on the green emitting layer. The efficiency of solution processed green PHOLEDs was more than quadrupled using the double layer emitting structure fabricated by the stamp transfer printing method.