Luminescence of heat-treated silicon-based polymers: Promising materials for LED applications

Ilaria Menapace, Gabriela Mera, Ralf Riedel, Emre Erdem, Rüdiger A. Eichel, Alberto Pauletti, Graham A. Appleby

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37 Citations (Scopus)

Abstract

A new strategy to obtain transparent, thermally stable, and formable photoluminescent materials for LED applications is presented. Starting from commercially available silicon-based polymers, luminescence properties are developed by means of simple heat treatment. Solid polymethylsilsesquioxane MK (Wacker-Besil®PMS MK) and liquid poly(ureamethylvinyl)silazane Ceraset (Kion Ceraset® PUVMS) were thermally treated between 200 and 700 °C for 2 h under Ar atmosphere. Photoluminescence properties were observed in all the samples. The structural rearrangements during thermal annealing were effective in order to red-shift the emission spectra of the untreated polymers to the visible range. The formation of dangling bonds and carbon sp2, associated with the annealing procedure and confirmed by means of Electron Paramagnetic Resonance (EPR) spectroscopy and solid state Magic Angle Spinning NMR (MAS-NMR) contribute to the red-shift of the photoluminescence emissions of the polymers. After heat treatment at low temperatures (200, 300, and 400 °C), both the polymers show fluorescence in the UV range. While the polysiloxane reveals white luminescence after annealing at 500 and 600 °C, the polysilazane heat-treated at 500 °C exhibits emission in the blue-green range and is transparent. At higher temperatures the presence of free carbon counteracts the luminescence properties.

Original languageEnglish
Pages (from-to)5790-5796
Number of pages7
JournalJournal of Materials Science
Volume43
Issue number17
DOIs
Publication statusPublished - Sep 2008
Externally publishedYes

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ASJC Scopus subject areas

  • Materials Science(all)
  • Mechanics of Materials
  • Mechanical Engineering

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