Fabrication Of White Organic Light-Emitting Devices Utilizing Color Conversion Films And Study About Their Performance

White organic light emitting devices (WOLEDs) show a widely potential application in the solid state lighting and flat panel display due to its high brightness, wide viewing angle, low power consumption, flexible and simple technology compared to other display and lighting devices. As one of methods to achieve WOLED, the technology that combine color conversion film (CCL) and Blue Light-Emitting Device have tremendous development potential driven by its merits in commercialization.This thesis focus on the investigation of WOLED, which is basis on the combination color conversion film(CCL) and blue OLED devices, particularly on the conversion efficiency for CCL and the enhancement for WOLED. The important achievements obtained are summarized as follows.1. Exploration and research on CCL materials. MEH-PPV is employed as a red light conversion materials to realize WOLED combine with blue OLED, which is fabricated use highly efficient blue fluorescent materials N-BDAVBi. Upon the excitation of blue light, CCL emits red light and then mix with the transmission blue light to realize white device. The influence of MEH-PPV doped concentration is demonstrated, current density, maximum brightness and current efficiency are 0.25mA/cm2, 14117cd/m2 and 8.02 cd /A, respectively, as the doping concentration is 6mg/ml. The fluorescence quantum yield was only 1.8%, however, although MEH-PPV can be used as CCL material. Alteratively, a high fluorescence quantum yield blue-green organic material Lumogen Yellow S 0790 used as a conversion coating and its properties are investigated, combining with different emission spectra of blue devices. Pure white light emission device with excellent stably property is obtained as while as the thickness of CCL in an optimization value. Furthermore, the mixture of MEH-PPV and Lumogen Yellow S 0790 act as CCL and the performance of device is studied. The fabricated devices present full color emission and range the entire white region through tuning the CCL. The color coordinates of (0.32, 0.34) and maximum current efficiency 5.34cd/A are obtained, which imply the feasibility of CCL to realize WOLED with blue OLED.2. Improvement of performance for blue OLED. N-BDAVBi highly efficient blue fluorescent material and its effect of doping concentration in host on performances for single-layer device is optimized, Two, threeand four light-emitting layer devices are investigated further. With the increase of light-emitting layer, the composite light-emitting region is widened. As a result, performances of devices are significantly improved because of the carrier balance in the emitting layer and their compound probabilities are enhanced, reaching a maximum brightness of 50000cd/m2. Maximum current and power efficiency are18.99 cd/A and 11.63 lm/W as the current density is 2.0 mA/cm2.3. Conclusions on WOLED combination of CCL and blue OLED and the further works have to do are presented.