Abstract
An efficient cathode structure for organic light-emitting diodes (OLEDs) using Al together with a 2,3-diphenyl-5-hydroxyquinoxalinolato lithium (LiDPQX) interlayer has been demonstrated. The electron injection ability of LiDPQX is superior to that of LiF at a low driving current owing to the high energy level match between the emitting layer and LiDPQX. A mechanism involving a chemical reaction between Al and LiDPQX, and the self-doping of LiDPQX was proposed and proved by quantum computation.