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Highly transparent thermal stable silicone/titania hybrids with high refractive index for LED encapsulation

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Abstract

Silicone/titania hybrids for LED encapsulation were synthesized via hydrolysis and condensation reaction between tetrabutyl titanate and silica sol containing phenyl groups and long alkyl chains. Crack-free thick films (~1 mm) were fabricated by curtain painting. The hybrid films with different Ti contents were characterized by FTIR, UV–VIS, TGA/DSC, AFM, TEM, ellipsometer, etc. Results show that the hybrid films contain long alkyl chains which have high thermal stability against yellowing owing to the steric hindrance given by long alkyl chains. The hybrid films have high transmittance (≥98% in visible range) and high refractive index (1.591–1.681). In LED encapsulation, the silicone/titania hybrids with an RI of 1.605 increased the light extraction efficiency of bare blue LEDs by 19.4%.

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Acknowledgments

The authors acknowledge the supports of Guangdong Industry-University-Research Cooperation Project of the Ministry of Education (2012A090300004), Shanghai Nano Science and Technology Special Project (12nm0500300), Shanghai Superior Young Teachers Culture Program (B.37-0407-11-003), and Shanghai Municipal Education Commission (J50102).

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  1. Nano Science and Technology Research Center, Shanghai University, Shanghai, 200444, China

    Yawen Lai, Lujiang Jin, Jianzhong Hang, Xiaoying Sun & Liyi Shi

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  1. Yawen Lai
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  2. Lujiang Jin
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  4. Xiaoying Sun
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  5. Liyi Shi
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Correspondence to Jianzhong Hang.

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Lai, Y., Jin, L., Hang, J. et al. Highly transparent thermal stable silicone/titania hybrids with high refractive index for LED encapsulation. J Coat Technol Res 12, 1185–1192 (2015). https://doi.org/10.1007/s11998-015-9681-4

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