彩色有机薄膜电致发光及动态矩阵显示

Color Organic Thin Film Electroluminescence and Passive Matrix Display

研究了绿色、红色、蓝色和白色 4种有机薄膜电致发光器件。通过掺杂得到了高稳定性的绿色及红色器件 ,绿色器件的半寿命达 1 4 0 0 0小时 (初始亮度 1 0 0cd/m2 ) ,红色器件的半寿命为 75 0 0小时 (初始亮度 5 0cd/m2 )。还研究了具有空穴锁定层及非锁定层的多种不同结构和材料的蓝色及白色器件。研究表明无论蓝色还是白色器件 ,具有空穴锁定层的器件稳定性较差 ,老化过程中界面势垒的变化很大。非锁定层的蓝色及白色器件中 ,新材料JBEM比DPVBi有更优越的性能。JBEM构成的蓝色器件的半亮度寿命为 1 0 35小时 (初始亮度 1 0 0cd/m2 )。由JBEM构成的白色器件中 ,由蓝色及红色掺杂在同一层的器件得到最好的稳定性 ,其半亮度寿命为 2 80 0小时 (初始亮度 1 0 0cd/m2 ) ,而且它具有发光颜色不随电流变化而变化的特点。在稳定性改善的基础上研制成功 96× 6 0线 ,分辨率为 2线 /mm的绿色及白色矩阵显示屏 ,还利用选择蒸发的方法制造了彩色矩阵屏 ,设计和研制了驱动及控制电路 。

Green, red, blue and white organic light emitting diodes (OLEDs) were investigated. Remarkable improvement in stability has been demonstrated in doped green and red devices. The QA doped green OLED achieved a long life time of 14 000 hours at initial luminance of 100cd/m 2.The red OLED doped with red dye DCJTB showed high stability,the half decay time reached 7 500 hours at the initial luminance of 50cd/m 2. Three blue device were constructed as following: ITO/CuPc/NPB/TPBi/Alq/MgAg (Cell BT); ITO/CuPc/NPB/DPVBi∶Perylene/Alg/Alq/MgAg(Cell BD); ITO/CuPc/NPB/JBEM∶Perylene/Alq/MgAg(Cell BJ). Here TPBi is a hole blocking meterial,DPVBi is a blue host,and JBEM is a new blue emitting mate- rial.On basis of the blue devices,putting the red dopant DCJTB into blue material TPBi,DPVBi,JBEM,or green host Alq,four white devices were produced. Experimental shows that the blue cell and white cell with blocking layer TPBi had much shorter life time than that of the conventional cell.It is obvious that the blocking layer is not favorable to the stability of the device,it may be attributed to the high barrier between the hole transporting and blocking layers.For the blue devices with JBEM as the host or DPVBi as the host,the former has better stability than the latter,showing the life time of 1 035 hours at initial luminance of 100cd/m 2.For the white OLEDs,just like the blue devices,the cell with JBEM as the host had better performance than that with DPVBI as the host,and the device with blue dye and red dye DCJTB in the same layer showed high stability,the half decay time reached 2846 hours at initial luminance of 100cd/m 2. A green,white panel display with 96×60 pixels and resolution of 2 lines/mm are constructed. The driving circuit was designed to eliminate the cross-talk between the pixels, a good image was realized.