Open AccessFDTD analysis of the light extraction efficiency of OLEDs with a random scattering layer
Author(s) -
Jun-Whee Kim,
Jae Hoon Jang,
MinCheol Oh,
Junhwa Shin,
DooHee Cho,
Jaehyun Moon,
Jeong Ik Lee
Publication year - 2014
Publication title -
optics express
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.22.000498
Subject(s) - finite difference time domain method , oled , materials science , optics , molar absorptivity , attenuation coefficient , quantum efficiency , absorption (acoustics) , optoelectronics , scattering , light scattering , layer (electronics) , physics , nanotechnology
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.