White light-emitting diodes(WLEDs)fabricated by single-phase full color emitting phosphor are an emerging solution for health lighting.The crystallographic site occupation of activators in a proper host lattice is cru...White light-emitting diodes(WLEDs)fabricated by single-phase full color emitting phosphor are an emerging solution for health lighting.The crystallographic site occupation of activators in a proper host lattice is crucial for sophisticated design of such phosphor.Here,we report a high quality white lightemitting phosphor Ba_(2)Ca(BO_(3))_(2):Ce^(3+)(K^(+)),Eu^(2+),Mn^(2+)with spectral distribution covering whole visible region.Blue light emission originates from Ce3+ions occupying preferentially Ba^(2+)site by controlling synthesis conditions.Green and red lights are obtained from Eu^(2+)occupying Ba2+(and Ca)site and Mn2+occupying Casite,respectively.In this triple-doped phosphor,strong red emission with a low concentration of Mn2+is realized by the efficient energy transfer from Ce3+and Euto Mn.Furthermore,high quality white light is accomplished by properly tuning the relative doping amount of Ce^(3+)(K^(+))/Eu^(2+)/Mn^(2+)based on efficient simultaneous energy transfer.The results indicate that Ba_(2)Ca(BO_(3))_(2):Ce^(3+)(K^(+)),Eu^(2+),Mn^(2+)is a promising white light-emitting phosphor in WLEDs application.展开更多
A white emitting phosphor Ba2Ca(BO3)2:Dy3+ was synthesized via a high temperature solid state reaction at 1000℃ for 5 h. The luminescence, mole fraction quenching and thermal stability of Ba2Ca(BO3)2:Dy3+ were invest...A white emitting phosphor Ba2Ca(BO3)2:Dy3+ was synthesized via a high temperature solid state reaction at 1000℃ for 5 h. The luminescence, mole fraction quenching and thermal stability of Ba2Ca(BO3)2:Dy3+ were investigated. According to the phase composition analyzed by X-ray powder diffraction, there is no crystalline phase except Ba2Ca(BO3)2 in the sample. Ba2Ca(BO3)2:Dy3+ can produce white emission under 348 nm excitation. The emission intensities of Ba2Ca(BO3)2:Dy3+ are affected by Dy3+ concentration. The concentration quenching effect was analyzed, and the concentration quenching mechanism was verified as dipole-dipole interaction. The critical distance(R c) obtained based on the crystal structure data is 2.911 nm. At 150℃, the emission intensity of Ba2Ca(BO3)2:Dy3+ is 68.0% of the initial value at room temperature. The activation energy for the thermal quenching calculated is 0.202 e V. Moreover, the CIE chromaticity coordinates of Ba2Ca(BO3)2:Dy3+ locate in the white region of(0.319, 0.356).展开更多
基金Project supported by the National Key Research and Development Plan of China(2019YFE0107200)the Natural Science Foundation of Hubei Province(2020CFB700)+4 种基金the Doctoral Researchof Hubei University of Arts and Science(kyqdf2020023)Innovation Research Team Project of Hubei University of Arts and Science(2020kypytd001)the Project of Hubei University of Arts and Science(XK2021027)the National Natural Science Foundation of China(10804099)Natural Science Foundation of Zhejiang Province(LZ18B050002)。
文摘White light-emitting diodes(WLEDs)fabricated by single-phase full color emitting phosphor are an emerging solution for health lighting.The crystallographic site occupation of activators in a proper host lattice is crucial for sophisticated design of such phosphor.Here,we report a high quality white lightemitting phosphor Ba_(2)Ca(BO_(3))_(2):Ce^(3+)(K^(+)),Eu^(2+),Mn^(2+)with spectral distribution covering whole visible region.Blue light emission originates from Ce3+ions occupying preferentially Ba^(2+)site by controlling synthesis conditions.Green and red lights are obtained from Eu^(2+)occupying Ba2+(and Ca)site and Mn2+occupying Casite,respectively.In this triple-doped phosphor,strong red emission with a low concentration of Mn2+is realized by the efficient energy transfer from Ce3+and Euto Mn.Furthermore,high quality white light is accomplished by properly tuning the relative doping amount of Ce^(3+)(K^(+))/Eu^(2+)/Mn^(2+)based on efficient simultaneous energy transfer.The results indicate that Ba_(2)Ca(BO_(3))_(2):Ce^(3+)(K^(+)),Eu^(2+),Mn^(2+)is a promising white light-emitting phosphor in WLEDs application.
文摘A white emitting phosphor Ba2Ca(BO3)2:Dy3+ was synthesized via a high temperature solid state reaction at 1000℃ for 5 h. The luminescence, mole fraction quenching and thermal stability of Ba2Ca(BO3)2:Dy3+ were investigated. According to the phase composition analyzed by X-ray powder diffraction, there is no crystalline phase except Ba2Ca(BO3)2 in the sample. Ba2Ca(BO3)2:Dy3+ can produce white emission under 348 nm excitation. The emission intensities of Ba2Ca(BO3)2:Dy3+ are affected by Dy3+ concentration. The concentration quenching effect was analyzed, and the concentration quenching mechanism was verified as dipole-dipole interaction. The critical distance(R c) obtained based on the crystal structure data is 2.911 nm. At 150℃, the emission intensity of Ba2Ca(BO3)2:Dy3+ is 68.0% of the initial value at room temperature. The activation energy for the thermal quenching calculated is 0.202 e V. Moreover, the CIE chromaticity coordinates of Ba2Ca(BO3)2:Dy3+ locate in the white region of(0.319, 0.356).
