利用色彩转换法制备高色稳定性的柔性白色有机电致发光器件

本文利用色转换方法,将高效的蓝色柔性有机电致发光器件(flexible organic light emitting devices, FOLEDs)与色转换材料(color conversion material, CCM)相结合,制备了柔性白色有机电致发光器件(white organic light emitting devices, WOLEDs).首先利用2, 3, 5, 6-Tetrafluoro-7, 7, 8, 8-tetracyano-quinodimethane (F4-TCNQ)和4, 4', 4"-tris-(N-3-methylphenyl-N-phenylamino) tripheny-lamine (m-MTDATA)组成的多量子阱(multiple quantum well, MQW)结构作为空穴注入层(hole injection layer, HIL)结合新型蓝光材料N⁶, N⁶, N¹², N¹²-tetrap-tolylchrysene-6, 12-diamine (NCA)制备出高效的蓝光FOLEDs,然后将其与色转换材料4-(dicyanomethylene)-2-tert-butyl-6-(1,1,7,7-tetramethyljulolidyl-9-enyl)-4H-pyran (DCJTB) 结合,通过沉积不同厚度的CCM来优化白光器件的发光光谱,获得了色稳定性较高的白光. 实验结果表明:在驱动电压为7 V, DCJTB的厚度为120 nm时得到较接近白光等能点的色坐标 (0.33, 0.27),且当驱动电压由6 V升至11 V 时,器件的色坐标变化仅为(±0.02, ±0.02), 表现出高色稳定性.

Highly color-stability flexible white organic light-emitting devices fabricated by color conversion method

We demonstrate flexible white organic light-emitting diode (WOLED) with high color stability, which combines vacuum deposited blue flexible organic light-emitting diode (FOLED) with red surface color conversion material (CCM). Firstly, we utilize the novel multiple quantum well (MQW), which consists of the alternate layers of 2, 3, 5, 6-Tetrafluoro-7, 7, 8, 8-tetracyano-quinodimethane (F4-TCNQ) and 4, 4', 4"-tris-(N-3-methylphenyl-N-phenylamino) tripheny-lamine (m-MTDATA) as hole injection layer (HIL), through combining a new blue emitting material of N⁶, N⁶, N¹², N¹²-tetrap-tolylchrysene-6, 12-diamine (NCA), to fabricate highly efficient blue FOLED. Then, the CCM of 4-(dicyanomethylene)-2-tert-butyl-6-(1, 1, 7, 7-tetramethyljul-oli-dyl-9-en-yl)-4H-pyran (DCJTB) is deposited on the outside of the ITO flexible substrate. Finally, the thickness of the color conversion film (CCF) is optimized to improve the color purity of flexible WOLED. The results demonstrate that at a driving voltage of 7 V, the CIE coordinates of (0.33, 0.27) which are very close to the white equal-energy area are obtained with the thickness of DCJTB of 120 nm. Moreover, the CIE coordinate migrations of the flexible WOLED are less than (±0.02, ±0.02) in a wide range of driving voltages (from 6 V to 11 V) for the device, indicating the flexible WOLED has excellent color stability.