【摘 要】
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Exploring and designing new luminescent host with rich resource is beneficial to reducing the cost and the large-scale application of luminescent materials.Here
【机 构】
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College of Chemistry and Materials Science,Huaibei Normal University,Huaibei 235000,China;College of
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Exploring and designing new luminescent host with rich resource is beneficial to reducing the cost and the large-scale application of luminescent materials.Herein,a series of novel Eu3+-activated KNa5-Ca5(CO3)8 red-emitting phosphors with different Eu3+ concentrations were successfully synthesized under mild hydrothermal condition.XRD and SEM characterizations show that all as-prepared KNa5Ca5(CO3)8∶Eu3+ samples crystallize in a hexagonal structure,P63mc (No.186) space group,and show monodispersed hexagonal sheet morphologies,within a side length interval about of 2-3 μm and a thickness of about 0.6 μm.Eu3+ doping within 6 mol％ concentration has little influence on the crystal structure of the host,as indicated by XRD,and FT-IR results,but thermal stability changes as shown by the TG-DTA.KNa5Ca5(CO3)8 phosphors with different Eu3+ concentrations can emit red-light under effectively excitation by near-UV light.CIE chromaticity coordinates of all KNa5Ca5(CO3)8∶Eu3+ phosphors were calculated to locate in red region,and CCT of each sample is the range from 2815 to 3650 K,very close to the tungsten lamp light.Besides,concentration quenching phenomenon appearing at 5 mol％ is found to be the result of electric multipolar interaction of Eu3+ activators,and the decay lifetime is about 1.63 ms,which almost unchanges with Eu3+ doping concentration.Importantly,thermal quenching analysis reveals good thermal stability with thermal activation energy of about 0.216 eV.The results reported here demonstrate that KNa5Ca5(CO3)8 is a promising fluorescent host for LEDs applications.
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