Polarizable H-Bond Concept in Aromatic Poly(thiourea)s: Unprecedented High Refractive Index, Transmittance, and Degradability at Force to Enhance Lighting Efficiency

Seigo Watanabe, Luca M. Cavinato, Vladimir Calvi, Richard van Rijn, Rubén D. Costa*, Kenichi Oyaizu*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

2 Citations (Scopus)

Abstract

Developing transparent and highly refractive environmentally friendly polymers has not been realized yet toward sustainable optoelectronics. This work describes poly(thiourea)s (PTUs) design following a new “polarizable group synergy” concept, combining highly polarizable hydrogen bonding groups and aromatic-based spacers to form densely packed and high-refractive-index polymer networks. Specifically, PTUs containing m- and p-phenylene spacers exhibit an easy synthesis, high thermostability (Tg = 159 °C), visible transparency (>92%T at 1 µm-film), ultra-high refractive index (nD = 1.81) based on the random H-bonding arrays with a high packing constant (Kp = 0.738), and straightforward preparation of flexible films via solvent-based techniques. Capitalizing on these assets, PTU-films are integrated into benchmark graphene-based lighting device architectures based on the light-emitting electrochemical cells (LECs) concept. A joint optical modeling and experimental validation confirm the increase in external quantum efficiency expected by the enhanced light out-coupling of PTU-films. Finally, PTUs are efficiently depolymerized to low molecular weight compounds by simply adding diamines under heating, following the dynamic covalent bond exchange between thiourea moieties. Overall, this work highlights the PTU family as new promising materials with a unique polarizable H-bond design to meet efficient and sustainable thin-film lighting devices.

Original languageEnglish
Article number2404433
JournalAdvanced Functional Materials
Volume34
Issue number42
DOIs
Publication statusPublished - 2024 Oct 15

Keywords

  • easy degradability
  • high refractive index
  • light outcoupling
  • light-emitting electrochemical cells
  • polythiourea

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • General Chemistry
  • Biomaterials
  • General Materials Science
  • Condensed Matter Physics
  • Electrochemistry

Fingerprint

Dive into the research topics of 'Polarizable H-Bond Concept in Aromatic Poly(thiourea)s: Unprecedented High Refractive Index, Transmittance, and Degradability at Force to Enhance Lighting Efficiency'. Together they form a unique fingerprint.

Cite this