Enhance Color Rendering Index via Full Spectrum Employing the Important Key of Cyan Phosphor

Mu-Huai Fang; Chenchen Ni; Xuejie Zhang; Yi-Ting Tsai; Sebastian Mahlik; Agata Lazarowska; Marek Grinberg; Hwo-Shuenn Sheu; Jyh-Fu Lee; Bing-Ming Cheng; Ru-Shi Liu

doi:10.1021/acsami.6b10233

Enhance Color Rendering Index via Full Spectrum Employing the Important Key of Cyan Phosphor

ACS Appl Mater Interfaces. 2016 Nov 16;8(45):30677-30682. doi: 10.1021/acsami.6b10233. Epub 2016 Nov 4.

Authors

Affiliations

¹ Department of Chemistry, National Taiwan University , Taipei 106, Taiwan.
² Institute of Experimental Physics, Faculty of Mathematics, Physics and Informatics, University of Gdańsk , 80-308 Gdańsk, Poland.
³ National Synchrotron Radiation Research Center , Hsinchu 300, Taiwan.
⁴ Department of Mechanical Engineering and Graduate Institute of Manufacturing Technology, National Taipei University of Technology , Taipei 106, Taiwan.

PMID: 27802017
DOI: 10.1021/acsami.6b10233

Abstract

A new concept called "full-spectrum lighting" has attracted considerable attention in recent years. Traditional devices are usually combined with ultraviolet-light-emitting diode (LED), red, green, and blue phosphors. However, a cyan cavity exists in the 480-520 nm region. Hence, cyan phosphors are needed to compensate for the cavity. (Sr,Ba)₅(PO₄)₃Cl:Eu²⁺ phosphors feature an extremely unique and tunable photoluminescence spectrum. Nevertheless, the tuning mechanisms of these phosphors remain unclear. In this study, we elucidate the mechanism of the cation size-controlled activator uneven-occupation and reoxidation in (Sr,Ba)₅(PO₄)₃Cl:Eu²⁺ phosphors. This mechanism could help tune the optical properties of related apatite families and structures with multiple cation sites and strongly uneven occupation of activators and cations. Finally, the package of the LED device is constructed to show that both color rendering index Ra and R9 are higher than 95. Thus, the device could be a potential candidate for full-spectrum lighting.

Keywords: LED; M5(PO4)3Cl; activator redistribution; cyan phosphor; full spectrum.