Fabrication of Photonic Crystal Structures on Flexible Organic Light-Emitting Diodes by Using Nano-Imprint and PDMS Mold

Ting-Lin Ho,Quang-Cherng Hsu,Yu-Liang Chen,Bao-Hsin Liu,M Jawaid,El-R Kenawy

doi:10.1051/matecconf/20166706085

Ting-Lin Ho, Quang-Cherng Hsu + Show 4 more

Open Access

https://doi.org/10.1051/matecconf/20166706085

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Abstract

In this paper, nanoimprint lithography was used to create a photonic crystals structure film in organic light-emitting diode (OLED) component, and then compare the efficiency of components whether with nanostructure or not. By using two different kinds of mold, such as silicon mold and PDMS mold, the nano structures in PMMA (molecular weight of 350K) were fabricated. Nanostructures in period of 403.53nm with silicon mold and nano structures in period of 385.64nm with PDMS mold as photonic crystal films were fabricated and were integrated into OLED. In experimental results, the OLED without photonic crystal films (with packing) behaves 193.3cd/m 2 for luminous intensity, 3.481cd/A for lightening efficiency (η L ) and 0.781 lm/W for lightening power (η P ) where V is 14V and I is 5.5537mA; the OLED with photonic crystal films (with packing) behaves 241.6cd/m 2 for luminous intensity, 4.173cd/A for lightening efficiency (η L ) and 0.936 lm/W for lightening power (η P ) where voltage of 14V and current (I) of 5.7891mA, which shows that the latter perform is well.

Highlights

organic light-emitting diode (OLED) is often to combine with nano/micro structure to enhance light extraction whose common methods are as follows: application scattering layer on the OLED surface [1], to cover an ordered microlens arrays [2], using anodic aluminum oxide (AAO) ¿lms [3], and applied photonic crystal technology [4,5,6,7]
PDMS solution poured onto a silicon stamp, and it was baked in an oven, the PDMS stamp was stripped from silicon stamp
A positive photoresist of AZ-4620 used into make the anode in polyethylene terephthalate (PET) /indium-tin oxide (ITO) structure

Summary

Introduction

OLED is often to combine with nano/micro structure to enhance light extraction whose common methods are as follows: application scattering layer on the OLED surface [1], to cover an ordered microlens arrays [2], using anodic aluminum oxide (AAO) ¿lms [3], and applied photonic crystal technology [4,5,6,7]. In the technology of photonic crystal, usually use nanoimprint lithography (NIL) to fabricate. Several NIL have been developed like in the following example: UV-NIL [6], soft lithography [9], a combined nanoimprint and photolithography (CNP) patterning technique [10, 11], Laser-Assister Direct Imprint (LADI) process [12], and reversal imprinting [13]. In the stand NIL, the transferred pattern will be fail (or broken) due to the pattern size is too small or imprinted stress is too big, etc. and a reversal imprinting is developed

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