Open AccessSurface wrinkle formation by liquid crystalline polymers for significant light extraction enhancement on quantum dot light-emitting diodes
Author(s) -
Sooyoung Yeom,
Hakjeon Kim,
Kitae Kim,
Chul Woong Joo,
Hyunjin Cho,
Hyunsu Cho,
Sukyung Choi,
Wonjun Lee,
Yeon Sik Jung,
ByoungHwa Kwon,
JunHee Na
Publication year - 2020
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.401328
Subject(s) - materials science , light emitting diode , diode , quantum efficiency , optics , optoelectronics , microstructure , polymer , distributed ray tracing , substrate (aquarium) , oled , quantum dot , wrinkle , ray tracing (physics) , physics , composite material , oceanography , layer (electronics) , geology
We propose an optimal outcoupling structure of a quantum-dot light-emitting diode (QLED) and present material properties based on numerical calculations via the ray-tracing method, in which light extraction properties are obtained according to the surface wrinkles on a substrate. After analyzing the designed microstructure elements, the optimal model was derived and applied to the QLEDs; consequently, the outcoupling efficiency enhanced by 31%. The liquid crystalline polymer forming the random surface wrinkles not only achieves an excellent light extraction through plasma crosslinking but also facilitates large-area processes. We propose an optical design rule for high-efficiency QLED design by analyzing the electro-optical efficiency, emission spectrum, and angular radiation pattern of the optical device.