Study Of White Organic Light-emitting Devices Combining Highly Efficient Blue Devices With Color Conversion Layers

White organic light-emitting devices （WOLEDs） shows a large potential application inthe solid state lighting and flat panel display due to its high brightness, wide viewing angle,lower power consumption, and flexible merit, et al.. And the technology combing bluedevices with color conversion layers has attracted much attention, because of its simplefabrication process, low cost, et al.. Thus, it is meaningful to study on this technology.This thesis mainly focus on the investigation of WOLED, which is realized byincorporating color conversion layer （CCL） and blue OLED, including the fabrication of CCLand the performance enhancement of the blue OLED. The detailed contents are as follows:1. The fabrication of the CCL. The DCJTB as CCL is fabricated by vacuum deposition orspin coating, respectively. For vacuum deposition, when its thickness is adjusted to 170 nm,the CIE coordinates of the WOLED is （0.34, 0.33） at 8 V, and while the driving voltageincreases from 6 V to 11 V, its CIE coordinates just shift from （0.36, 0.34） to （0.32, 0.32）. Themaximum luminescence and current efficiency are 1, 348 cd/m²and 1.37 cd/A, respectively.Then in order to simplify the fabrication technology, spin coating is employed to prepare theCCL. It is seemed that the performances of the device are almost equal with that of the devicewhose CCL is prepared by vacuum deposition.2. Performance enhancement of blue OLEDs. First, a LiF interlayer is inserted into holetransport layer to adjust the balance of holes and electrons in emission layer. The maximumcurrent efficiency of the blue OLED based on TC-1759 is enhanced from 3.85 cd/A to 5.21cd/A. Second, a CuPc electron buffer layer is employed which improves the injection ofelectrons, and the performance of the blue OLED is improved obviously, too. When thethickness of CuPc and MoO₃are optimized, the maximum luminescence and currentefficiency of the blue OLED are improved to 24, 060 cd/m²and 5.66 cd/A, respectively.3. Performance improvement of WOLEDs. For the device by blocking holes, themaximum current efficiency is enhanced from 1.37 cd/A to 1.78 cd/A. For the device byincreasing electrons, the maximum luminescence and the maximum current efficiency areimproved to 3, 764 cd/m²and 1.88 cd/A, and its CIE coordinates is （0.34, 0.33） at 8 V.4. Conclusions on WOLED which is realized by incorporating CCL with blue OLEDtogether with the plan of the further work are put forward.