Kim Jun-Whee, Jang Ji-Hyang, Oh Min-Cheol, Shin Jin-Wook, Cho Doo-Hee, Moon Jae-Hyun, Lee Jeong-Ik
Opt Express. 2014 Jan 13;22(1):498-507. doi: 10.1364/OE.22.000498.
The light extraction efficiency of OLEDs with a nano-sized random scattering layer (RSL-OLEDs) was analyzed using the Finite Difference Time Domain (FDTD) method. In contrast to periodic diffraction patterns, the presence of an RSL suppresses the spectral shift with respect to the viewing angle. For FDTD simulation of RSL-OLEDs, a planar light source with a certain spatial and temporal coherence was incorporated, and the light extraction efficiency with respect to the fill factor of the RSL and the absorption coefficient of the material was investigated. The design results were compared to the experimental results of the RSL-OLEDs in order to confirm the usefulness of FDTD in predicting experimental results. According to our FDTD simulations, the light confined within the ITO-organic waveguide was quickly absorbed, and the absorption coefficients of ITO and RSL materials should be reduced in order to obtain significant improvement in the external quantum efficiency (EQE). When the extinction coefficient of ITO was 0.01, the EQE in the RSL-OLED was simulated to be enhanced by a factor of 1.8.
使用时域有限差分（FDTD）方法分析了具有纳米级随机散射层的有机发光二极管（RSL - OLED）的光提取效率。与周期性衍射图案不同，RSL的存在抑制了相对于视角的光谱偏移。对于RSL - OLED的FDTD模拟，引入了具有一定空间和时间相干性的平面光源，并研究了相对于RSL填充因子和材料吸收系数的光提取效率。将设计结果与RSL - OLED的实验结果进行比较，以确认FDTD在预测实验结果方面的有效性。根据我们的FDTD模拟，限制在ITO - 有机波导内的光被快速吸收，为了在外部量子效率（EQE）方面获得显著提高，应降低ITO和RSL材料的吸收系数。当ITO的消光系数为0.01时，模拟得出RSL - OLED中的EQE提高了1.8倍。
