Long lasting phosphorescence (LLP) was observed in Eu2+, Ce3+ co-doped strontium borate glasses prepared under the reducing atmosphere due to the emission of both Eu2 + and Ce3+ . The methods of photoluminescence, the...Long lasting phosphorescence (LLP) was observed in Eu2+, Ce3+ co-doped strontium borate glasses prepared under the reducing atmosphere due to the emission of both Eu2 + and Ce3+ . The methods of photoluminescence, thermolu-minescence and phosphorescence were used to study the samples, and possible mechanism was suggested. The co-doping of Ce3 + ions poisoned the phosphorescence emission of Eu2 + because of the competition to obtain the trapped electron . The phosphorescence of Ce3 + in the sample decays more quickly than that of Eu2 + , which is suggested for the reason that the emission energy of Ce3 + is higher or the distance between Ce3 + and electron traps of the glasses is longer.展开更多
Long lasting phosphorescence （LLP） and photo-stimulated long lasting phosphorescence （PSLLP） were observed in Tb^3＋-doped strontium borosilicate glasses. The green phosphorescence arises fromf-f transitions of T...Long lasting phosphorescence （LLP） and photo-stimulated long lasting phosphorescence （PSLLP） were observed in Tb^3＋-doped strontium borosilicate glasses. The green phosphorescence arises fromf-f transitions of Tb^3＋ and can be observed with naked eyes in the dark for up to 10 hours after the irradiation with a UV lamp （λmax =254 nm） for 30 min at room temperature. The glass could re-emit LLP under the stimulation of a UV lamp （λmax=366 rim） for 60 seconds after the LLP disappeared. The re-emitted LLP is called PSLLP. The glass sample was characterized by the fluorescence and thermoluminescence spectra, respectively. The possible mechanism of the LLP and PSLLP was also discussed.展开更多
Mn^2＋ doped ZnO-P2O5 glasses emit red fluorescence, which shows that Mn^2＋ ion doped in zinc phosphate glass is octahedrally coordinated. Moreover, glass samples exhibit bright red long lasting phosphorescence （LLP...Mn^2＋ doped ZnO-P2O5 glasses emit red fluorescence, which shows that Mn^2＋ ion doped in zinc phosphate glass is octahedrally coordinated. Moreover, glass samples exhibit bright red long lasting phosphorescence （LLP） when the mole percent of ZnO are more than 60%. After turnoff the irradiation source of UV lamp peaking at 254 nm, the red phosphorescence can be observed for about 6 h in the limit of light perception for naked eyes （0.32 mcd/m^2）. Photoluminescence （PL） spectra, LLP emission spectra and decay curves were detected. Increasing MnO or ZnO content, the phosphorescence intensity can be improved distinctly and the emission wavelength can be also adjusted from 595 nm to 628 nm. According to the structural characteristic of zinc phosphates glasses, we suggest that non-bridge oxygen （NBO） is probably related with the arising of LLE Meantime, the variation of crystal field intensity induced that the LLP emission wavelength red shifts.展开更多
Long lasting phosphorescence phosphors with composition of (Sr1–xSmx)2ZnSi2O7 were prepared by conventional high-temperature solid-state method. Their properties were systematically investigated utilizing XRD, photol...Long lasting phosphorescence phosphors with composition of (Sr1–xSmx)2ZnSi2O7 were prepared by conventional high-temperature solid-state method. Their properties were systematically investigated utilizing XRD, photoluminescence, phosphorescence and thermoluminescence spectra. The results showed that these phosphors emitted reddish orange light that corresponds to the characteristic emission due to the 4G5/2→6H5/2, 6H7/2 and 6H9/2 transitions of Sm3+. After the UV light excitation source was switched off, th...展开更多
The exploration of novel long lasting red phosphors is still of importance due to expected commercial applications and scientific interests. In this work, we reported the red long lasting phosphorescence（LLP） from E...The exploration of novel long lasting red phosphors is still of importance due to expected commercial applications and scientific interests. In this work, we reported the red long lasting phosphorescence（LLP） from Eu^3＋ doped BiOCl semiconductor polycrystals. The LLP property of the red phosphor is relatively weak due to less trap density, but the excitation band of LLP stems from the energy gap transition of semiconductor, offering experimental evidence for energy transfer between BiOCl semiconductor and Eu^3＋ ions. Although the afterglow duration of Eu^3＋ doped BiOCl was short temporarily, this work may open a novel kind of red LLP phosphors.展开更多
Red long lasting phosphorescence（LLP） was firstly observed in LaA103：Eu3＋ phosphor synthesized by solid state method at 1773 K. It reveals that the Eu3＋ ions occupy the asymmetric La3＋ sites, resulting in the or...Red long lasting phosphorescence（LLP） was firstly observed in LaA103：Eu3＋ phosphor synthesized by solid state method at 1773 K. It reveals that the Eu3＋ ions occupy the asymmetric La3＋ sites, resulting in the orange-red emission of Eu3＋. The LLP of the optimum LaA103：0.6%Eu3＋ sample can come to about 2000 s according to a definition of 0.32 mcd/m2. The LLP decay curve can not be fitted even by a function of three exponential terms, due to the complicated retrapping process of carriers. The result of a classical multi-peak fitting method on thermo- luminescence reveals that the excellent LLP performance of LaA103：Eu3＋ material originates from the rich distribu- tion of shallow traps（E=0.7875 eV）.展开更多
A novel phosphor of un-doped Sr Zr Si2O7 material with blue long lasting phosphorescence which could be recorded for about 5400 s（0.32 mcd/m^2） was developed. It revealed that both the emission centers and traps lev...A novel phosphor of un-doped Sr Zr Si2O7 material with blue long lasting phosphorescence which could be recorded for about 5400 s（0.32 mcd/m^2） was developed. It revealed that both the emission centers and traps levels were related to the oxygen-deficient defects which were induced in reducing atmosphere. The filling and fading experiments indicated that the traps levels in Sr Zr Si2O7 were continuous in distribution. The influence of shallow traps on deep traps was investigated and the important role of the bridge effect was revealed. The un-doped Sr Zr Si2O7 material obtained in reducing atmosphere showed potential application as a cheap blue long lasting phosphorescence phosphor.展开更多
A new aluminosilicate long-lasting phosphor with composition of NaA1SiO4：Eu2＋,Ho3＋ was synthesized and investigated. Under UV light excitation, the phosphor emitted yellow light corresponding to the characteristic ...A new aluminosilicate long-lasting phosphor with composition of NaA1SiO4：Eu2＋,Ho3＋ was synthesized and investigated. Under UV light excitation, the phosphor emitted yellow light corresponding to the characteristic emission of Eu2＋ due to 5d-4f transi- tion. Bright yellow phosphorescence sustaining for more than 30 rain was observed after ceasing the excitation. The phosphorescence intensity decay obeyed a fl decay law, indicating a tunneling electron-hole recombination process in the phosphor. Four peaks ap- peared in the thermoluminescence curve and the ones at 322 and 370 K were thought to account for the long lasting phosphorescence at room temperature. The Ho3＋ ion incorporated into the phosphor did not give any light but dramatically increased the intensities of both photoluminescence and phosphorescence via promoting defect levels in the phosphor.展开更多
Luminescence and defect properties of novel phosphor β-Zn 3(PO 4) 2:Zr 4+ were systematically investigated. Corresponding to its lowest optical absorption transition at 240 nm, phosphor emits a bluish-green light...Luminescence and defect properties of novel phosphor β-Zn 3(PO 4) 2:Zr 4+ were systematically investigated. Corresponding to its lowest optical absorption transition at 240 nm, phosphor emits a bluish-green light at 485 nm, which yields the Stokes shift about 20000 cm -1. The unusual optical properties of Zr 4+ ion are ascribed to its uncommon coordination environment. In addition it shows intensive bluish-green long lasting phosphorescence (LLP) due to the existence of electron trap, which is generated by aliovalent substitution of Zr 4+ ion for the cation site in the matrix as shown in thermoluminescence (TL) spectrum.展开更多
基金Project supported by Technological Key Project of Basic Research of Jilin Province (20020601)
文摘Long lasting phosphorescence (LLP) was observed in Eu2+, Ce3+ co-doped strontium borate glasses prepared under the reducing atmosphere due to the emission of both Eu2 + and Ce3+ . The methods of photoluminescence, thermolu-minescence and phosphorescence were used to study the samples, and possible mechanism was suggested. The co-doping of Ce3 + ions poisoned the phosphorescence emission of Eu2 + because of the competition to obtain the trapped electron . The phosphorescence of Ce3 + in the sample decays more quickly than that of Eu2 + , which is suggested for the reason that the emission energy of Ce3 + is higher or the distance between Ce3 + and electron traps of the glasses is longer.
基金Funded by the Project-sponsored by SRF for ROCS,SEM
文摘Long lasting phosphorescence （LLP） and photo-stimulated long lasting phosphorescence （PSLLP） were observed in Tb^3＋-doped strontium borosilicate glasses. The green phosphorescence arises fromf-f transitions of Tb^3＋ and can be observed with naked eyes in the dark for up to 10 hours after the irradiation with a UV lamp （λmax =254 nm） for 30 min at room temperature. The glass could re-emit LLP under the stimulation of a UV lamp （λmax=366 rim） for 60 seconds after the LLP disappeared. The re-emitted LLP is called PSLLP. The glass sample was characterized by the fluorescence and thermoluminescence spectra, respectively. The possible mechanism of the LLP and PSLLP was also discussed.
基金Funded by the State Key Project of Basic Research of China(No.GB1998061312)
文摘Mn^2＋ doped ZnO-P2O5 glasses emit red fluorescence, which shows that Mn^2＋ ion doped in zinc phosphate glass is octahedrally coordinated. Moreover, glass samples exhibit bright red long lasting phosphorescence （LLP） when the mole percent of ZnO are more than 60%. After turnoff the irradiation source of UV lamp peaking at 254 nm, the red phosphorescence can be observed for about 6 h in the limit of light perception for naked eyes （0.32 mcd/m^2）. Photoluminescence （PL） spectra, LLP emission spectra and decay curves were detected. Increasing MnO or ZnO content, the phosphorescence intensity can be improved distinctly and the emission wavelength can be also adjusted from 595 nm to 628 nm. According to the structural characteristic of zinc phosphates glasses, we suggest that non-bridge oxygen （NBO） is probably related with the arising of LLE Meantime, the variation of crystal field intensity induced that the LLP emission wavelength red shifts.
基金Project supported by the National Basic Research Program of China (2007CB935502)
文摘Long lasting phosphorescence phosphors with composition of (Sr1–xSmx)2ZnSi2O7 were prepared by conventional high-temperature solid-state method. Their properties were systematically investigated utilizing XRD, photoluminescence, phosphorescence and thermoluminescence spectra. The results showed that these phosphors emitted reddish orange light that corresponds to the characteristic emission due to the 4G5/2→6H5/2, 6H7/2 and 6H9/2 transitions of Sm3+. After the UV light excitation source was switched off, th...
基金Project supported by the National Natural Science Foundation of China(61465006,61265007)Reserve talents Project of Yunnan Province(2015HB013)
文摘The exploration of novel long lasting red phosphors is still of importance due to expected commercial applications and scientific interests. In this work, we reported the red long lasting phosphorescence（LLP） from Eu^3＋ doped BiOCl semiconductor polycrystals. The LLP property of the red phosphor is relatively weak due to less trap density, but the excitation band of LLP stems from the energy gap transition of semiconductor, offering experimental evidence for energy transfer between BiOCl semiconductor and Eu^3＋ ions. Although the afterglow duration of Eu^3＋ doped BiOCl was short temporarily, this work may open a novel kind of red LLP phosphors.
基金the National Natural Science Foundation of China（No. 11264033） and the Science Research Foundation of Tianshui Normal University, China（No.TSA 1108）.
文摘Red long lasting phosphorescence（LLP） was firstly observed in LaA103：Eu3＋ phosphor synthesized by solid state method at 1773 K. It reveals that the Eu3＋ ions occupy the asymmetric La3＋ sites, resulting in the orange-red emission of Eu3＋. The LLP of the optimum LaA103：0.6%Eu3＋ sample can come to about 2000 s according to a definition of 0.32 mcd/m2. The LLP decay curve can not be fitted even by a function of three exponential terms, due to the complicated retrapping process of carriers. The result of a classical multi-peak fitting method on thermo- luminescence reveals that the excellent LLP performance of LaA103：Eu3＋ material originates from the rich distribu- tion of shallow traps（E=0.7875 eV）.
基金supported by the National Natural Science Young Foundation of China(51202099)the Gansu Provincial Department of Finance Project(BH2012-017)the Gansu Province University Research Foundation(2013B-059)
文摘A novel phosphor of un-doped Sr Zr Si2O7 material with blue long lasting phosphorescence which could be recorded for about 5400 s（0.32 mcd/m^2） was developed. It revealed that both the emission centers and traps levels were related to the oxygen-deficient defects which were induced in reducing atmosphere. The filling and fading experiments indicated that the traps levels in Sr Zr Si2O7 were continuous in distribution. The influence of shallow traps on deep traps was investigated and the important role of the bridge effect was revealed. The un-doped Sr Zr Si2O7 material obtained in reducing atmosphere showed potential application as a cheap blue long lasting phosphorescence phosphor.
基金Project supported by the Funds for Creative Research Groups of China(21221061)
文摘A new aluminosilicate long-lasting phosphor with composition of NaA1SiO4：Eu2＋,Ho3＋ was synthesized and investigated. Under UV light excitation, the phosphor emitted yellow light corresponding to the characteristic emission of Eu2＋ due to 5d-4f transi- tion. Bright yellow phosphorescence sustaining for more than 30 rain was observed after ceasing the excitation. The phosphorescence intensity decay obeyed a fl decay law, indicating a tunneling electron-hole recombination process in the phosphor. Four peaks ap- peared in the thermoluminescence curve and the ones at 322 and 370 K were thought to account for the long lasting phosphorescence at room temperature. The Ho3＋ ion incorporated into the phosphor did not give any light but dramatically increased the intensities of both photoluminescence and phosphorescence via promoting defect levels in the phosphor.
文摘Luminescence and defect properties of novel phosphor β-Zn 3(PO 4) 2:Zr 4+ were systematically investigated. Corresponding to its lowest optical absorption transition at 240 nm, phosphor emits a bluish-green light at 485 nm, which yields the Stokes shift about 20000 cm -1. The unusual optical properties of Zr 4+ ion are ascribed to its uncommon coordination environment. In addition it shows intensive bluish-green long lasting phosphorescence (LLP) due to the existence of electron trap, which is generated by aliovalent substitution of Zr 4+ ion for the cation site in the matrix as shown in thermoluminescence (TL) spectrum.
