Non-rare earth impurity doped Sr2CeO4：X （X ：Zn, Hg, Al, Ag, Cr） phosphors are prepared by using the combustion method. The structural and photoluminescent properties of the as-prepared phosphors are investigated b...Non-rare earth impurity doped Sr2CeO4：X （X ：Zn, Hg, Al, Ag, Cr） phosphors are prepared by using the combustion method. The structural and photoluminescent properties of the as-prepared phosphors are investigated by X-ray diffraction （XRD） and photoluminescence at room temperature. Experimental results show that zinc addition and firing processing can effectively enhance the photoluminescence of Sr2CeO4 phosphors.展开更多
Citric acid complexing sol-gel auto-combustion method was explored to synthesize superfine Sr2CeO4 phosphors using the inorganic salts Sr（NO3）2 and Ce（NO3）3 as raw materials together with citric acid （CA） as a c...Citric acid complexing sol-gel auto-combustion method was explored to synthesize superfine Sr2CeO4 phosphors using the inorganic salts Sr（NO3）2 and Ce（NO3）3 as raw materials together with citric acid （CA） as a chelating agent. TGDTA, XRD, SEM and photoluminescence spectra were used to investigate the formation process, microstructure and luminescent properties of the synthesized Sr2CeO4. The results show that the crystallization of Sr2CeO4 begins at about 800 ℃ and completes around 900 ℃ with an orthorhombic structure. When the calcination temperature is above 1000 ℃, Sr2CeO4 partly decomposes into SrCeO3. SEM studies show that the particles of Sr2CeO4 obtained at 900 ℃ are sphericallike shape and superfine with diameter below 100 nm. The excitation spectrum of the superfine Sr2CeO4 phosphors displays a broad band with two peaks around 290 and 350 nm respectively. The former peak is stronger than the latter one. This broad band is due to the charge transfer （CT） band of the Ce^4＋ ion. Excited by a radiation of 290 nm, the superfine phosphors emit a strong blue-white fluorescence, and the emission spectrum shows a broad band with a peak around 470 nm, which can be assigned to the f→t1g transition of Ce^4＋ . It is found that the emission intensity is affected by the calcination temperature.展开更多
Undoped and Eu3+-doped Sr2CeO4 luminescent materials were prepared by sol-gel method. The structure and uncommon photoluminescence of Sr2CeO4∶Eu3+ phosphors were investigated in detail by powder X-ray diffraction (XR...Undoped and Eu3+-doped Sr2CeO4 luminescent materials were prepared by sol-gel method. The structure and uncommon photoluminescence of Sr2CeO4∶Eu3+ phosphors were investigated in detail by powder X-ray diffraction (XRD), Raman spectrum, and photoluminescence spectrum, respectively. The XRD results demonstrate that the as-prepared Sr2CeO4 phosphor is single phase and well crystallized. For Sr2CeO4∶Eu3+ phosphor, its excitation spectrum consists of a broad intense band from host and Eu3+-O2-charge transfer and a number of small peaks from Eu3+ ion. The broad emission band originated from Sr2CeO4 host and Eu3+ emission lines in the blue, green, and red regions coexist. Not only the characteristic transition lines from the lowest excited 5D0 level of Eu3+ but also those from higher energy levels 5DJ (J=1, 2) of Eu3+ ions are observed. These unusual luminescence properties result from the low vibration energy of Sr2CeO4 host-lattice and different energy transfer process from host to activator.展开更多
基金Project supported by the National Science Foundation for Post-doctoral Scientists of China (Grant No.20090461331)
文摘Non-rare earth impurity doped Sr2CeO4：X （X ：Zn, Hg, Al, Ag, Cr） phosphors are prepared by using the combustion method. The structural and photoluminescent properties of the as-prepared phosphors are investigated by X-ray diffraction （XRD） and photoluminescence at room temperature. Experimental results show that zinc addition and firing processing can effectively enhance the photoluminescence of Sr2CeO4 phosphors.
文摘Citric acid complexing sol-gel auto-combustion method was explored to synthesize superfine Sr2CeO4 phosphors using the inorganic salts Sr（NO3）2 and Ce（NO3）3 as raw materials together with citric acid （CA） as a chelating agent. TGDTA, XRD, SEM and photoluminescence spectra were used to investigate the formation process, microstructure and luminescent properties of the synthesized Sr2CeO4. The results show that the crystallization of Sr2CeO4 begins at about 800 ℃ and completes around 900 ℃ with an orthorhombic structure. When the calcination temperature is above 1000 ℃, Sr2CeO4 partly decomposes into SrCeO3. SEM studies show that the particles of Sr2CeO4 obtained at 900 ℃ are sphericallike shape and superfine with diameter below 100 nm. The excitation spectrum of the superfine Sr2CeO4 phosphors displays a broad band with two peaks around 290 and 350 nm respectively. The former peak is stronger than the latter one. This broad band is due to the charge transfer （CT） band of the Ce^4＋ ion. Excited by a radiation of 290 nm, the superfine phosphors emit a strong blue-white fluorescence, and the emission spectrum shows a broad band with a peak around 470 nm, which can be assigned to the f→t1g transition of Ce^4＋ . It is found that the emission intensity is affected by the calcination temperature.
基金Project supported bythe JSTUFoundation of Science Research (KYY05039)
文摘Undoped and Eu3+-doped Sr2CeO4 luminescent materials were prepared by sol-gel method. The structure and uncommon photoluminescence of Sr2CeO4∶Eu3+ phosphors were investigated in detail by powder X-ray diffraction (XRD), Raman spectrum, and photoluminescence spectrum, respectively. The XRD results demonstrate that the as-prepared Sr2CeO4 phosphor is single phase and well crystallized. For Sr2CeO4∶Eu3+ phosphor, its excitation spectrum consists of a broad intense band from host and Eu3+-O2-charge transfer and a number of small peaks from Eu3+ ion. The broad emission band originated from Sr2CeO4 host and Eu3+ emission lines in the blue, green, and red regions coexist. Not only the characteristic transition lines from the lowest excited 5D0 level of Eu3+ but also those from higher energy levels 5DJ (J=1, 2) of Eu3+ ions are observed. These unusual luminescence properties result from the low vibration energy of Sr2CeO4 host-lattice and different energy transfer process from host to activator.
