An anti-reflection (AR) coating system was inserted between the anode (ITO) and the glass substrate in the red light
organic electroluminescent devices (OLED) for the structure being K9/ITO/NPB (60nm)/DCJTB (0.3nm)/Alq3 (60nm)/
LiF(0.3nm)/Al. The AR film system structure was K9/TiO2/Al2O3/2-ITO, and the optical thicknesses of TiO2 and Al2O3
coatings were also quarter wave length. The results indicated that the maximum transmissivity of AR coating was by
95 %( 610nm); it increased by 8% compared with only using ITO as AR coating. The average luminance increased by
about 30%, the average energy efficiency increased by about 60%, while reducing the threshold voltage of the devices.
The processing is simple and high efficient, and can change AR coating structure according to the OLED device
different emission wavelength, therefore, can be widely applied to the OLED devices.
The thin aluminum nitride(AlN) film using as an insulating layer was inserted between the anode (ITO) and the NPB
organic film in the organic light-emitting devices(OLED) for the structure being K9/ITO/AlN/NPB/Alq3/LiF/Al.The
effect of the different thickness AlN film on the device performance was investigated. After optimization, improvement
of OLEDs properties is biggest when the AlN film thickness is about 0.4nm.Such a structure with AlN layer facilitates
the increase of current density and decrease of threshold voltage, resulting in an improved luminance and energy
efficiency. The average luminance increased by about 30% and an improvement of 21.8% on the average current density.
The lifetime experiment of the devices has proved an improvement on stability because of inserted AlN film. This
phenomenon is mainly because of the insulating capability of the aluminum nitride coating and the passivation role of
AlN film to the ITO surface. The processing is simple and high efficient, can be widely applied to the OLED devices.
Two dimeric trimeric phenylenvinylene derivative 2, 5, 2', 5'-tetrakis (4'-fluorostyryl) biphenyl (P-F-TSB) and 2, 5, 2', 5'-tetra (p-trifluoromethylstyryl)-biphenyl (TFM-TSB) have been synthesized as new electroluminescent (EL) materials. P-F-TSB exhibits good color purity, high luminance of blue light-emission in organic light-emitting devices. Maximum brightness and luminous efficiency are of 1828 cd/m2 and of 1.92 cd/A, respectively. CIE coordinates are x=0.20 and y=0.22. Interestingly, we can fabricate single layer white light-emitting device using TFM-TSB as emitting layer. The broad electroluminescence emission band may attribute to long-wavelength excimer and electromer emission in addition to the blue component from singlet excited state of individual TFM-TSB molecule. Furthermore, white-light emission can also be obtained with a typical three-layer structure of ITO/ NPB (50 nm)/ TFM-TSB (50 nm)/ Alq3 (30 nm)/LiF/Al device. The maximum brightness of this device is 809 cd/m2 at 217 mA/cm2 and 13V, and the maximum luminous efficiency is 1.49 cd/A at 11 mA/ cm2 and 8V.