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Planarized and Compact Light Scattering Layers Based on Disordered Titania Nanopillars for Light Extraction in Organic Light Emitting Diodes
Author(s) -
Donie Yidenekachew J.,
Theobald Dominik,
Moghadamzadeh Somayeh,
Mertens Adrian,
Hossain Ihteaz M.,
Paetzold Ulrich W.,
Lemmer Uli,
Gomard Guillaume
Publication year - 2021
Publication title -
advanced optical materials
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.89
H-Index - 91
ISSN - 2195-1071
DOI - 10.1002/adom.202001610
Subject(s) - materials science , oled , nanopillar , optoelectronics , photoresist , light scattering , fabrication , layer (electronics) , scattering , optics , nanostructure , nanotechnology , medicine , physics , alternative medicine , pathology
In this work, the extraction of waveguided and substrate modes in organic light emitting diodes (OLEDs) is improved by using compact light scattering layers composed of a disordered 2D array of TiO 2 nanopillars. The TiO 2 nanopillars are fabricated by combining a self‐assembly and a solvent‐assisted lift‐off process, and are further planarized by a 250 nm thin epoxy‐based photoresist layer to facilitate their anode deposition and integration within the OLED stack. This fabrication route allows engineering internal light outcoupling elements with a limited amount of parasitic absorption and with easily tunable light scattering properties that are effective over a broad spectral and angular range. Taking the example of a monochromatic bottom emitting OLED ( λ p e a k= 520 nm), the authors demonstrate an efficiency enhancement of +22% rel upon the incorporation of the planarized light extraction layer as well as ameliorated angular emission characteristics. This approach can be integrated in a high‐throughput fabrication routine and straightforwardly extended to other OLED layouts.