Waterproof Alkyl Phosphate Coated Fluoride Phosphors for Optoelectronic Materials

Hoang-Duy Nguyen; Chun Che Lin; Ru-Shi Liu

doi:10.1002/anie.201504791

Waterproof Alkyl Phosphate Coated Fluoride Phosphors for Optoelectronic Materials

Angew Chem Int Ed Engl. 2015 Sep 7;54(37):10862-6. doi: 10.1002/anie.201504791. Epub 2015 Jul 23.

Authors

Hoang-Duy Nguyen^{1

2}, Chun Che Lin¹, Ru-Shi Liu^{3

4}

Affiliations

¹ Department of Chemistry, National Taiwan University, Taipei, 106 (Taiwan).
² Institute of Applied Materials Science, Vietnam Academy of Science and Technology, Hochiminh City, 700000 (Vietnam).
³ Department of Chemistry, National Taiwan University, Taipei, 106 (Taiwan). rsliu@ntu.edu.tw.
⁴ Department of Mechanical Engineering and Graduate Institute of Manufacturing Technology, National Taipei University of Technology, Taipei, 106 (Taiwan). rsliu@ntu.edu.tw.

PMID: 26214154
DOI: 10.1002/anie.201504791

Abstract

A facile approach for coating red fluoride phosphors with a moisture-resistant alkyl phosphate layer with a thickness of 50-100 nm is reported. K2 SiF6 :Mn(4+) particles were prepared by co-precipitation and then coated by esterification of P2 O5 with alcohols (methanol, ethanol, and isopropanol). This route was adopted to encapsulate the prepared phosphors using transition-metal ions as cross-linkers between the alkyl phosphate moieties. The coated phosphor particles exhibited a high water tolerance and retained approximately 87 % of their initial external quantum efficiency after aging under high-humidity (85 %) and high-temperature (85 °C) conditions for one month. Warm white-light-emitting diodes that consisted of blue InGaN chips, the prepared K2 SiF6 :Mn(4+) phosphors, and either yellow Y3 Al5 O12 :Ce(3+) phosphors or green β-SiAlON: Eu(2+) phosphors showed excellent color rendition.

Keywords: light-emitting diodes; phosphors; photoluminescence; white light.