Mingcai Li,Xuejie Zhang,Yinjian Zheng,Yaliang Xu,Haoran Zhang,Yingliang Liu,Bingfu Lei
The discovery of light converter excited by near-ultraviolet (UV) superior broadband blue-emitting lighting source is a main challenge in plant growth LEDs. In this study, SrLu 2 O 4 :Ce 3+ , Li + , F − blue phosphor has been synthesized via a solid-state reaction. Benefitting from doping of F − ions, SrLu 2 O 4 :Ce 3+ , Li + , F − phosphor (λ ex = 405 nm, λ em = 460 nm) shows a strong broadband (FWHM = 90 nm) blue-emitting with lower critical concentration of Ce 3+ ions and an increasing 6.9% thermal quenching performance (92.1% @ 423 K of the peak intensity at room temperature). Moreover, a blue light converter composed of SrLu 2 O 4 :Ce 3+ , Li + , F − phosphor and glass matrix is obtained based on phosphor-in-glass (PiG) technology, exhibiting excellent thermal stability and outstanding moisture resistance . A red light converter with commercial red phosphor is obtained by the same method. Furthermore, by combining of two light converters with near-UV chip, a proof-of-concept plant growth high power LED is achieved and applied in indoor Italian lettuce growing in comparison with commercial plant lamps.
Guanghao Li,Yang Zhao,Jiao Xu,Zhiyong Mao,Jingjing Chen,Dajian Wang
Two strategies, deviation of stoichiometry and addition of flux, were employed in this work to suppress the emergence of AlN impurity in the synthesis of CaAlSiN 3 :Eu 2+ phosphors under condition of atmospheric pressure. The influence of Al atoms deviation from ideal stoichiometry and SrF 2 flux addition on the suppression of AlN impurity and their resultant photoluminescence properties are investigated for CaAlSiN 3 :Eu 2+ phosphors. For a special Eu 2+ doping concentration (0.02 mol), AlN impurity was suppressed effectively when Al element deviation is 0.2 mol (CaAl 0.8 SiN 3 ) and the SrF 2 flux addition is 7 wt% during preparation of CaAlSiN 3 :Eu 2+ phosphors, respectively. The luminescent properties of CaAlSiN 3 :Eu 2+ phosphors are found to be enhanced significantly owing to the suppression of AlN impurity. In addition, the suppression mechanisms of AlN impurity in atmospheric pressure-synthesized CaAlSiN 3 :Eu 2+ phosphors are discussed. These results indicate the promising prospect for our proposed strategies in preparing high performance CaAlSiN 3 :Eu 2+ phosphors under the condition of atmospheric pressure.