Energy down converting organic fluorophore functionalized mesoporous silica hybrids for monolith-coated light emitting diodes

Markus Börgardts,Thomas J J Müller

doi:10.3762/bjoc.13.76

Markus Börgardts, Thomas J J Müller

Open Access

https://doi.org/10.3762/bjoc.13.76

Copy DOI

Abstract

The covalent attachment of organic fluorophores in mesoporous silica matrices for usage as energy down converting phosphors without employing inorganic transition or rare earth metals is reported in this article. Triethoxysilylpropyl-substituted derivatives of the blue emitting perylene, green emitting benzofurazane, and red emitting Nile red were synthesized and applied in the synthesis of mesoporous hybrid materials by postsynthetic grafting to commercially available MCM-41. These individually dye-functionalized hybrid materials are mixed in variable ratios to furnish a powder capable of emitting white light with CIE chromaticity coordinates of x = 0.33, y = 0.33 and an external quantum yield of 4.6% upon irradiation at 410 nm. Furthermore, as a proof of concept two different device setups of commercially available UV light emitting diodes, are coated with silica monoliths containing the three triethoxysilylpropyl-substituted fluorophore derivatives. These coatings are able to convert the emitted UV light into light with correlated color temperatures of very cold white (41100 K, 10700 K) as well as a greenish white emission with correlated color temperatures of about 5500 K.

Highlights

The development of new efficient illumination materials has received increasing attention in the past years [1,2,3]
A terminal triethoxysilyl group has to be coupled to luminescent dyes with blue, green, and red emission characteristics for generating hybrid materials with white light emission based upon additive color mixing
A rapid and versatile functionalization can be achieved upon ligating a triethylsiloxy-functionalized azide and a terminal alkynyl-functionalized luminophore by CuAAC (Cu-catalyzed azide–alkyne cycloaddition) [21,22,23]

Summary

Introduction

The development of new efficient illumination materials has received increasing attention in the past years [1,2,3]. We communicate our first efforts to design red, green, and blue light-emitting mesoporous materials from organic chromophores, their blending to white lightemitting silica hybrids based upon additive color mixing, and as a proof of principle, the implementation in a white light emitting monolith for down converting commercially available UV light emitting diodes. A terminal triethoxysilyl group has to be coupled to luminescent dyes with blue, green, and red emission characteristics for generating hybrid materials with white light emission based upon additive color mixing.

Results

Conclusion