A Simple Method for Fabricating an External Light Extraction Composite Layer with RNS to Improve the Optical Properties of OLEDs

In this study, we fabricated a random nanostructure (RNS) external light extraction composite layer containing high-refractive-index nanoparticles through a simple and inexpensive solution process and a low-temperature mask-free process. We focused on varying the shape and density of the RNSs and ad...

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Bibliographic Details
Main Authors: Geun-Su Choi, Shin-Woo Kang, Eun-Jeong Bae, Eun-Bi Jang, Dong-Hyun Baek, Byeong-Kwon Ju, Young-Wook Park
Format: Article
Language:English
Published: MDPI AG 2022-04-01
Series:Nanomaterials
Subjects:
Online Access:https://www.mdpi.com/2079-4991/12/9/1430
Description
Summary:In this study, we fabricated a random nanostructure (RNS) external light extraction composite layer containing high-refractive-index nanoparticles through a simple and inexpensive solution process and a low-temperature mask-free process. We focused on varying the shape and density of the RNSs and adjusted the concentration of the high-refractive-index nanoparticles to control the optical properties. The RNSs fabricated using a low-temperature mask-free process can use the distance between the nanostructures and various forms to control the diffraction and scattering effects in the visible light wavelength range. Consequently, our film exhibited a direct transmittance of ~85% at a wavelength of 550 nm. Furthermore, when the RNSs’ composite film, manufactured using the low-temperature mask-free process, was applied to organic light-emitting diodes (OLEDs), it exhibited an external quantum efficiency improvement of 32.2% compared with the OLEDs without the RNSs. Therefore, the randomly distributed high-refractive-index nanoparticles on the polymer film can reduce the waveguide mode and total reflection at the substrate/air interface. These films can be used as a scattering layer to reduce the loss of the OLED substrate mode.
ISSN:2079-4991