Characteristics of the organic single-quantum-well devices fabricated by the doping method

A doping technique to fabricate an organic quantum-well electroluminescent device is demonstrated. The fabricated single-quantum-well device consists of the following structure: an N,N′-Bis(3-methyphenyl)-N,N′-diphenylbenzidine layer for hole transportation, an 8-(quinolinolate)-aluminum(Alq) layer for electron transportation and a light emitting layer of Alq doped with 5,6,11,12-tetraphenylnaphthacene(rubrene). The dopant rubrene serves as a potential well, whereas the undoped Alq layer serves as a barrier layer. The efficiency and luminance of the device have been significantly improved. The observed phenomena of the spectral narrowing and the emission peak energy blue-shift are a result of the recombination of carriers from the quantized energy states.