A Single‐Step Hot Embossing Process for Integration of Microlens Arrays in Biodegradable Substrates for Improved Light Extraction of Light‐Emitting Devices
Name
admt.201900933.pdf
Description
Published version
Size
2.16 MB
Format
Adobe PDF
Checksum (MD5)
8ce29d1d7671dd3fedc2ee1ffd86a64a
Author(s)
Jürgensen, Nils
Fritz, Benjamin
Mertens, Adrian
Tisserant, Jean-Nicolas
Kolle, Mathias
Gomard, Guillaume
Hernandez-Sosa, Gerardo
Date Issued
2021
Journal
Advanced Materials Technologies
Publisher
Wiley
Version
Final published version
Abstract
© 2020 The Authors. Published by WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim Integration of light management solutions relying on biodegradable materials in organic light-emitting devices could assist the development of sustainable light sources or conformable and wearable display technology. Using industrially relevant processing techniques, it is shown that microlens arrays can be seamlessly integrated into flexible and biodegradable cellulose diacetate substrates to facilitate extraction of the trapped substrate modes in light-emitting electrochemical cells. The substrates are patterned for light extraction and optimized for scalable printing processes in a single step by thermally embossing microlenses with polydimethylsiloxane molds on one substrate surface and simultaneous flattening of the other. Furthermore, by implementing the biopolymer substrate with microlens arrays, the total volume fraction of biodegradable materials in the microlense equipped device is 99.94%. The embossed microstructures on the biopolymer substrates are investigated by means of scanning electron microscopy and the angular light extraction profile of the devices is measured and compared to ray tracing simulations. Light-emitting electrochemical cells with integrated microlens array substrates achieve an efficiency enhancement factor of 1.45, exceeding conventional organic light-emitting diodes on glass substrates with laminated microlens arrays (enhancement factor of 1.23).
MIT Department
Massachusetts Institute of Technology. Department of Mechanical Engineering
Terms of Use
Creative Commons Attribution 4.0 International license
Persistent DSpace Link
DOI of Published Version
https://doi.org/10.1002/admt.201900933
