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A novel blue-light-emitting material, 2,3,6,7-tetramethyl-9,10-dinaphthyl-anthracene (TMADN), was synthesized and characterized. Organic light-emitting diode (OLED), which has a double-layer structure, has been fabricated. In this OLED, the homemade TMADN was used as the light-emitting material and 4,7-diphenyl-1,10-phenanthroline (DPA) was used as the hole blocking/electron transporting material, N , N ′-biphenyl- N , N ′-bis-(1-naphenyl)-[1,1′-biphenyl]-4,4′-diamine (NPB) was used as the hole transporting material. The peak emission of electroluminescence (EL) is at about 456 nm and the CIE coordinates are (0.171, 0.228). The brightness of the device is up to 5600 cd/m 2 at 17 V with the maximum EL efficiency of 2.2 cd/A.

A novel 1,5-naphthylenediamine derivative, 1,5-bis[ N -(1-naphthyl)- N -phenyl]naphthalene diamine (NND), was designed and synthesized. This amine exhibited high glass transition temperature ( T g =127 °C) and hole transporting ability. The device with a structure of ITO/ N , N ′-bis(naphthalene-1-yl)- N , N ′-diphenyl-benzidine(NPB)/NND/2-(4- tert -butylphenyl)-5-(4-biphenyl)-1,3,4-oxadiazole (PBD)/Mg:Ag was fabricated and bright blue light emission was obtained with a peak wavelength of 432 nm, and the color coordinate in CIE chromaticity is (0.172, 0.126). The brightness of 250 cd/m 2 at 14 V was achieved.

The polytetrafluoroethylene (Teflon) was utilized as buffer layer to improve the performance of organic light emitting diodes (OLEDs). In the ITO/Teflon/ N , N ′-diphenyl- N , N ′-(3-methylphenyl)-1,1′-biphenyl-4,4′-diamine (TPD)/tris(8-hydroxy-quinoline) aluminum (Alq 3 )/Ca/Ag device, the Teflon film helped to enhance the hole tunneling injection and effectively impede indium diffusion from the ITO electrode. Compared with the devices without Teflon, the turn-on voltage was lowered by 1.5 V due to the introduction of Teflon buffer, and the optimized devices exhibited a luminous efficiency double that of the devices without Teflon layer, and the device lifetime proved to be dramatically increased.