HKBU chemists discover novel approach to generate dual-color photoluminescence material for optical thermal sensors

Persistent luminescence induced by the introduction of multi-valent Mn ions in K2LiBF6 (B=Al, Ga and In) fluoride phosphors

 

Mn4+ elpasolite with K2LiBF6 (B = Al, Ga and In) are known as red-emitting phosphors due to emission of red light upon excitation by near ultraviolet (NUV). These compounds are extensively used for phosphor-converted white light emitting diodes (WLEDs) application. The narrow emission bands of such fluorides have shown to significantly improve the performance of lower color temperature WLEDs.

 

Dr Hor Catherine Hong-Huan, Prof Wong Ka-Leung and Dr Li Liyi from the Department of Chemistry at HKBU came up with a novel approach to modify the emission band of the fluorides at lower temperatures. This was achieved by introducing Mn2+ as impurity in the elpasolite structure of the said fluorides, resulting in a broad emission band in the green to orange light under NUV excitation. The proposed fluorides exhibited longer persistent luminescence (PersL) which was attributed to Mn2+ ions. The research elaborated on synthesis and characterization of fluoride phosphors which have dual color emission properties and these materials can be extended for their application in development of optical thermal sensors. The article is now published in Chemical Engineering Journal 430(2022)132421.
https://doi.org/10.1016/j.cej.2021.132421

 

Source: Department of Chemistry Facebook Page



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