Highly Efficient Organic Light-Emitting Diodes Based On Donor-Acceptor Small Molecules

The authors have fabricated highly efficient organic light-emitting diodes from donor-acceptor small molecules, 2-(4-methyl-quinolin-2-yl)-10-phenyl-phenothiazine (MQPTZ) and 2-(4-phenyl-quinolin-2-yl)-10-phenyl-phenothiazine (PQPTZ). Their devices turned on at 4.0 V and emitted strong green light near 510 nm. The maximum luminance of 60 000 and 55 000 cd/m(2) at 10.4 V and the maximum power efficiencies of 5.75 and 2.5 lm/W at 5 V were obtained from the MQPTZ and the PQPTZ, respectively. The overall performance of their devices in terms of current-voltage, luminance, and external quantum efficiency were discussed and compared with those from the device with tris-(8-hydroxyquinolineolato) aluminum. (c) 2006 American Institute of Physics.