Organic light-emitting diodes based on novel organic materials

Organic light-emitting diodes (OLEDs) based on novel organic materials, N-carbazole end-capped oligofluorene-thiophene, 9,10-substituted anthracene and 2,7-substituted fluorine derivatives, have been fabricated and their electroluminescence (EL) emission spectra and performances were investigated. The N,N’-diphenyl-N-N’-bis(3-methylphenyl)-1,1’-biphenyl-4,4’-diamine (TPD) and 4,4’-bis[N-(1-naphthyl)-N-phenyl-amino] biphenyl (NPD) materials were used as reference organic materials in OLEDs. The use of N-carbazole end-capped oligofluorene-thiophene derivative materials as the emitting layers in OLEDs showed an emission color varied from blue to yellow with good performances, depending on the composition of the N-carbazole end-capped oligofluorene-thiophene compounds. The 9,10-substituted anthracene derivative compound end-capped with triphenylamine groups in the molecule used as a blue emitter in OLEDs was the best material for these anthracene derivative series while the fluorine derivative compound end-capped at 2 and 7 positions with pyrenyl groups acted as both super hole-transporting and blue emitting material with high thermal stabilities for OLEDs as these novel materials compared with the reference materials, TPD and NPD. Therefore, it suggests that these novel materials competitive materials to the TPD and NPD which were widely used materials in OLEDs.