High-brightness organic double-quantum-well electroluminescent devices

Abstract

An organic double-quantum-well structure electroluminescent device fabricated by a doping method is demonstrated. The device consists of N,N′-bis-(1-naphthl)-N,N′-diphenyl-1,1′-biphenyl-4,4′- diamine (NPB) used as a hole transporter, undoped tris(8-quinolinolato) aluminum (Alq) as a barrier potential or electron transporter, and Alq doped with 5,6,11,12-tetraphenylnaphthacene (rubrene) as a potential well and emitter, and has the following structure: indium tin oxide/NPB/ Alq:rubrene/Alq/Alq:rubrene/Alq/Mg/Al. The maximum brightness and efficiency reach 48000 cd/m2 and 4.59 lm/W, respectively. The present double-quantum-well structure device shows higher brightness and higher efficiency than those of the common heterostructure devices. © 2000 American Institute of Physics.