Y. Qiu et al., Preparation and characterization of high efficient blue-light emitting materials with a secondary ligand for organic electroluminescence, JPN J A P 1, 39(3A), 2000, pp. 1151-1153
In this paper, a blue light emitting material, bis(2-methyl-quinolinolato)(
phenolato) aluminum(III) (Alq(2)'OPh), was synthesized. Organic electrolumi
nescent (EL) devices have been fabricated with the homemade organometallic
compound as the emitting layer and N,N'-diphenyl-N,N'-di(m-tolyl)benzidinev
(TPD) as the hole transport layer, blue light emission with a high efficie
ncy was obtained. Compared with tris (8-hydroxyquinoline) aluminum (Alq(3))
, the presence of the phenolate ligand shifts the light emission to the blu
e region of the spectrum. The maximum wavelength of the EL is at around 495
nm and the brightness is up to 4000 cd/m(2) with the maximum efficiency up
to 1.41 m/W. Two new compounds have also been prepared in order to investi
gate the effect of the secondary ligand. The comparison study indicates tha
t the organometallic compound with a secondary ligand, not only the sterica
l effect but also some other effect would be responsible for the change of
the emission wavelength.