TBPe作蓝光材料的双层白色有机电致发光器件的性能

选用一种新型高效的蓝光有机小分子荧光染料TBPe,首次制备了以PVK:TBPe为蓝光发光层和Alq₃:rubrene为橙红光发光层的双层白光有机电致发光器件,器件结构为ITO/PVK:TBPe/Alq₃:rubrene/Mg:Ag。通过适当调节各有机层的掺杂比例和厚度,得到了发光性能比较理想的白光器件。器件在7V左右启亮,而且随着外加电压的变化,色坐标基本保持不变,在外加驱动电压为16V时,器件的亮度为738cd/m²,外量子效率为0.2%。我们还尝试选用本身可以发绿白光,而且兼具电子传输特性的母体材料Zn(BTZ)₂替代Alq₃,器件的最大亮度提高到1300cd/m²,色坐标为(0.32,0.36),更加接近白色等能点,器件其他光电性能也得到了显著地提高。

Characteristics of a Double Layers White Organic Electroluminescent Device Using TBPe as Dopant in a Blue Mixed Layer

White organic light-emitting devices(WOLED) have been attracting tremendous attention nowadays since from first being reported.They have many advantages such as their lightness and thinness,self light-(emission,) broad viewing angle,quick response,high efficiency,easy fabrication,low driving voltage,low(energy) consumption,low cost,etc.Therefore,they are becoming potential competitors in full color displays,backlights for liquid crystal displays and even next-generation of light sources.We fabricated a new type of white organic electroluminescent device using TBPe as blue fluorescent(dopant.) The configuration of the device is ITO/PVK:TBPe/Alq₃:rubrene/Mg:Ag.In the device, PVK,Alq₃ and rubrene are used as hole transport material,electron transport material and orange fluorescent dopant,(respectively).By adjusting the thickness of each emitting layer and the adulterated proportion properly,a white light with CIE coordinates of(0.26,0.33) was generated,which is located in the white-light region.The CIE coordinate stayed virtually constant when the voltage increased from 8 V to 16 V.The device had a(maximum)luminance of 738 cd/m²,a maximum external efficiency of(0.2%).For enhancing the brightness and chromaticity of the device,we attempted to use Zn(BTZ)₂ instead of Alq₃ as electron transport material.Bright white light,over 1300 cd/m²,was successfully obtained,and the maximum efficiency reached to(0.31)% at 8 V.In conclusion,the performance of the whole device was(increased) remarkably.We try to blend the polymer and small molecule organic material together as blue-light-emitting layer,which makes up the shortcoming for each other.The efficiency of white light-emitting is improved only by designing the device structure and changing the electron transport material reasonable.We make the device structure as simply as possible to satisfy the need of the practical use.