使用R-4B和GIrl作为磷光掺杂剂、CBP为主体、BPhen为发光层间隔层, 制备了包含红、绿双发光层的黄色磷光OLED器件。器件结构为ITO/MoO3(40 nm)/NPB(40 nm)/TCTA(10 nm)/CBP: GIrl(14%)(20 nm)/BPhen(x nm)/CBP: R-4B(6%)(10 nm)/BCP(10 nm)/Alq3(40 nm)/LiF(1 nm)/Al(1 000 nm)。BPhen位于两发光层之间, 具有调节载流子复合的功能, 其中x为BPhen的厚度。通过调整x的值, 研究了BPhen厚度对OLED器件发光性能的影响。实验结果表明, 适当厚度的BPhen层可以提高器件的发光亮度和电流效率。BPhen厚度为6 nm的器件性能最佳, 16 V驱动电压下的器件亮度最高可达11 270 cd/m2, 最大电流效率为24.35 cd/A, 而且绿光和红光波峰强度相近, 黄光颜色纯正, 色坐标趋近于(0.5, 0.5)。

We prepared yellow phosphorescent OLED devices, which used R-4B, GIrl as the green phosphorescent dopant, CBP as the main body material. We investigated the BPhen as spacer layer between the red and green emitting layers to regulate currieries recombination. The device structure was ITO/MoO3(40 nm)/NPB(40 nm)/TCTA(10 nm)/CBP: GIrl(14%)(20 nm)/BPhen(x nm)/CBP: R-4B(6%)(10 nm)/BCP(10 nm)/Alq3(40 nm)/LiF(1 nm)/Al (1 000 nm). In this structure, x referred to six different thickness of BPhen in the devices. We studied its luminescent properties and controlled its spectra by adjusting the thickness of BPhen. The results show that appropriate thickness of BPhen can improve the performance of the device. When the thickness of BPhen is 6 nm, the performance of the device is the optimum. The maximum brightness is 11 270 cd/m2 at 16 V, and the maximum efficiency is 24.35 cd/A. Meanwhile, the green and red peaks almost have the same intensity in the spectra which means the purest yellow of all devices, and the color coordinates close to (0.5, 0.5).