SrZnO2 ： Eu^3 ＋ , Li^＋ phosphor powder by long wavelength UV excitation was synthesized by conventional solid-state reaction method. XRD and PL were employed to characterize their properties. The resuits show that ...SrZnO2 ： Eu^3 ＋ , Li^＋ phosphor powder by long wavelength UV excitation was synthesized by conventional solid-state reaction method. XRD and PL were employed to characterize their properties. The resuits show that Eu^3＋ ions preferentially occupy Sr^2＋ asymmetry cationic sites, thus emitting 612 nm red light originated from ^5D0 to ^7F2 transition. The luminescent intensity can be greatly enhanced with incorporation of Li^＋ ions. The excitation efficiency in range of 350 - 400 nm also increases greatly due to incorporating Li ^＋ ions. SrZnO2 ： Eu^3 ＋ , Li^＋ is a promising redemitting phosphor by long wavelength UV excitation.展开更多
As an Hg-free lamp using phosphor, the Bi^3＋ and EH^3＋ co-doped Y2O2S phosphors were prepared and their luminescence properties under vacuum ultraviolet（VUV） excitation were investigated. The VUV photoluminescent ...As an Hg-free lamp using phosphor, the Bi^3＋ and EH^3＋ co-doped Y2O2S phosphors were prepared and their luminescence properties under vacuum ultraviolet（VUV） excitation were investigated. The VUV photoluminescent intensity of Y2O2S：Eu^3＋ was weak, however, considerably stronger red emission at 626 nm with good color purity was observed in Y2O2S：Eu^3＋,Bi^3＋ systems. Investigation on the photoluminescence reveals that the strong VUV luminescence of Y2O2S：Eu^3＋,Bi^3＋ at 147 nm is mainly because the Bi^3＋ acts as a medium and effectively performs the energy transfer process： Y^3＋-O^2-→Bi^3＋→Eu^3＋, while the intense emission band at 172 nm is attributed to the absorption of the characteristic ^1So-^1P1 transition of Bi^3＋ and the direct energy transfer from Bi^3＋ to Eu^3＋. The Y2O2S：Eu^3＋,Bi^3＋ shows excellent VUV optical properties compared with the commercial （Y,Gd）BO3：Eu^3＋. Thus, the Y2O2S：Eu^3＋,Bi^3＋ can be a potential red VUV-excited candidate applied in Hg-free lamps for backlight of liquid crystal display.展开更多
A series of Gd_5Si_(2)BO_(13):Eu^(3+)and non-rare earth Bi^(3+)ions doped Gd_5Si_(2)BO_(13):Eu^(3+)phosphors was successfully synthesized via high-temperature solid-state method,and the as-obtained phosphors were stud...A series of Gd_5Si_(2)BO_(13):Eu^(3+)and non-rare earth Bi^(3+)ions doped Gd_5Si_(2)BO_(13):Eu^(3+)phosphors was successfully synthesized via high-temperature solid-state method,and the as-obtained phosphors were studied on their phase structures,luminescence characteristics,thermal stability and luminescence lifetime.Transient fluorescence spectroscopy data show that the addition of Bi^(3+)can obviously enhance the emission intensity of Eu^(3+)in the near-ultraviolet band owing to energy transfer from Bi^(3+)to Eu^(3+).Besides,the addition of Bi^(3+)can improve the thermal stability of a single-doped phosphor Gd_5Si_(2)BO_(13):0.35Eu^(3+)from 70.33%to 87.45%at 150℃and the quantum yield from 58.80%to 78.61%at room temperature.Finally,Gd_5Si_(2)BO_(13):Eu^(3+),Bi^(3+)was used to encapsulate white light-emitting diodes(WLEDs)with green((Ba,Sr)_(2)SiO_(4):Eu^(2+))and blue(BaMgAI_(10)O_(17):Eu^(2+))commercial phosphors.The color rendering index of WLEDs was calculated to be larger than 90,and the color temperature was estimated to be 4300-4500 K,which demonstrate that Gd_5Si_(2)BO_(13):Eu^(3+),Bi^(3+)can be regarded as a red phosphor with great potential application.This paper can provide a new insight into design of high-efficiency phosphors by introducing non-rare earth Bi^(3+)ions via energy transfer from Bi^(3+)to Eu^(3+).展开更多
文摘SrZnO2 ： Eu^3 ＋ , Li^＋ phosphor powder by long wavelength UV excitation was synthesized by conventional solid-state reaction method. XRD and PL were employed to characterize their properties. The resuits show that Eu^3＋ ions preferentially occupy Sr^2＋ asymmetry cationic sites, thus emitting 612 nm red light originated from ^5D0 to ^7F2 transition. The luminescent intensity can be greatly enhanced with incorporation of Li^＋ ions. The excitation efficiency in range of 350 - 400 nm also increases greatly due to incorporating Li ^＋ ions. SrZnO2 ： Eu^3 ＋ , Li^＋ is a promising redemitting phosphor by long wavelength UV excitation.
基金Supported by the Project of the Combination of Industry and Research by the Ministry of Education of China and Guang-dong Province, China(No.0712226100023)
文摘As an Hg-free lamp using phosphor, the Bi^3＋ and EH^3＋ co-doped Y2O2S phosphors were prepared and their luminescence properties under vacuum ultraviolet（VUV） excitation were investigated. The VUV photoluminescent intensity of Y2O2S：Eu^3＋ was weak, however, considerably stronger red emission at 626 nm with good color purity was observed in Y2O2S：Eu^3＋,Bi^3＋ systems. Investigation on the photoluminescence reveals that the strong VUV luminescence of Y2O2S：Eu^3＋,Bi^3＋ at 147 nm is mainly because the Bi^3＋ acts as a medium and effectively performs the energy transfer process： Y^3＋-O^2-→Bi^3＋→Eu^3＋, while the intense emission band at 172 nm is attributed to the absorption of the characteristic ^1So-^1P1 transition of Bi^3＋ and the direct energy transfer from Bi^3＋ to Eu^3＋. The Y2O2S：Eu^3＋,Bi^3＋ shows excellent VUV optical properties compared with the commercial （Y,Gd）BO3：Eu^3＋. Thus, the Y2O2S：Eu^3＋,Bi^3＋ can be a potential red VUV-excited candidate applied in Hg-free lamps for backlight of liquid crystal display.
文摘A series of Gd_5Si_(2)BO_(13):Eu^(3+)and non-rare earth Bi^(3+)ions doped Gd_5Si_(2)BO_(13):Eu^(3+)phosphors was successfully synthesized via high-temperature solid-state method,and the as-obtained phosphors were studied on their phase structures,luminescence characteristics,thermal stability and luminescence lifetime.Transient fluorescence spectroscopy data show that the addition of Bi^(3+)can obviously enhance the emission intensity of Eu^(3+)in the near-ultraviolet band owing to energy transfer from Bi^(3+)to Eu^(3+).Besides,the addition of Bi^(3+)can improve the thermal stability of a single-doped phosphor Gd_5Si_(2)BO_(13):0.35Eu^(3+)from 70.33%to 87.45%at 150℃and the quantum yield from 58.80%to 78.61%at room temperature.Finally,Gd_5Si_(2)BO_(13):Eu^(3+),Bi^(3+)was used to encapsulate white light-emitting diodes(WLEDs)with green((Ba,Sr)_(2)SiO_(4):Eu^(2+))and blue(BaMgAI_(10)O_(17):Eu^(2+))commercial phosphors.The color rendering index of WLEDs was calculated to be larger than 90,and the color temperature was estimated to be 4300-4500 K,which demonstrate that Gd_5Si_(2)BO_(13):Eu^(3+),Bi^(3+)can be regarded as a red phosphor with great potential application.This paper can provide a new insight into design of high-efficiency phosphors by introducing non-rare earth Bi^(3+)ions via energy transfer from Bi^(3+)to Eu^(3+).
