The CaS∶Eu^(2+), Sm^(3+) powders were prepared by high-temperature solid method in a reducing atmosphere. The influences of temperature and fired-time on properties of samples were studied. XRD analysis shows that cr...The CaS∶Eu^(2+), Sm^(3+) powders were prepared by high-temperature solid method in a reducing atmosphere. The influences of temperature and fired-time on properties of samples were studied. XRD analysis shows that crystal structure of CaS has formed at 700 ℃. Spectrum analysis results show that the samples which were stimulated by 980 nm laser after excited by ultraviolet lamp emit red luminescence peaking at 649 nm.展开更多
Photo-stimulated luminescence(PSL) is the process in which trapped charges are released by photons and produce luminescence through recombination. The variegated optical characteristics of photostimulated phosphors(PS...Photo-stimulated luminescence(PSL) is the process in which trapped charges are released by photons and produce luminescence through recombination. The variegated optical characteristics of photostimulated phosphors(PSPs) have drawn increasing attention and a large body of work encompassing mechanism and application of PSPs has been addressed. The optical data storage capacity resulting from abundant defect states enables PSPs to be applied to information storage. Moreover, PSPs provide potential application for anti-counterfeiting, as color changes due to the tunneling process. Recently, near infrared(NIR) light PSPs have been developed, exhibiting enormous potential for in vivo bio-imaging, as the stable and high noise-signal ratio characteristic of PSL. In this review, we devote to introducing the development and process of PSPs, and the challenge and future advance have also been demonstrated.展开更多
X-ray activated near-infrared(NIR)persistent luminescence has promising application in biomedical luminous imaging.However,there are strict medical restrictions on X-ray dosage to avoid radiation disease.There is a ne...X-ray activated near-infrared(NIR)persistent luminescence has promising application in biomedical luminous imaging.However,there are strict medical restrictions on X-ray dosage to avoid radiation disease.There is a need to develop a simple strategy to improve persistent luminescence imaging quality using low-dose X-ray.NIR photo-stimulation can enhance the persistent luminescence intensity by transporting the stored energy from deep traps to shallow ones,so that enhanced upconversion-like NIR-to-NIR persistent luminescence imaging can be conducted after low-dose X-ray excitation.However,existing NIR persistent luminescence phosphors have limited absorption in the NIR.To realize optimized NIR photostimulation,Nd^(3+)is proposed as a potential sensitizer to enhance the absorption of persistent luminescence phosphor to 808 nm light.In this study,ZnGa_(2)O_(4):Sn_(0.1),Cr_(0.003),Nd_(0.01)(ZGSC-Nd)was synthesized with a persistent luminescence peak at~700 nm.After activation with 1 Gy of X-ray,its persistent luminescence attenuated to less than 5%of its original intensity after 2800 s.Interestingly,the nearly vanished persistent luminescence was enhanced 5 times after 808 nm photo-stimulation,which was assigned to Nd absorption.Thus,a pseudo-upconverted persistent luminescence from 808 to 700 nm was realized more efficiently.A Nd-sensitized NIR photo-stimulated persistent luminescence mechanism was proposed.This phenomenon was applied for improved luminous imaging of ZGSC-Nd labeled bone cement after a single low-dose X-ray imaging.This work provides an applicable strategy to realize better persistent luminescence imaging after low-dose X-ray activation and will be significant on designing X-ray activated persistent phosphors for biomedical application.展开更多
Trivalent rare-earth ions （La3＋,Pr3＋,Nd3＋,Sm3＋,Gd3＋,Tb3＋,Dy3＋,Ho3＋,Er3＋,Tm3＋,and Yb3＋） were investigated as the codoped auxiliary sensitizer for the electron trapping materials SrS：Eu2＋ in order to enha...Trivalent rare-earth ions （La3＋,Pr3＋,Nd3＋,Sm3＋,Gd3＋,Tb3＋,Dy3＋,Ho3＋,Er3＋,Tm3＋,and Yb3＋） were investigated as the codoped auxiliary sensitizer for the electron trapping materials SrS：Eu2＋ in order to enhance the fluorescence properties.It was found that Sm3＋ and Tb3＋ had the best photoluminescence stimulated luminescence （PSL） effect among the selected trivalent rare-earth ions.All the SrS：Eu2＋ samples doped by different trivalent rare-earth ions could be stimulated by 980 nm laser after being exposed to the conventional sunlight,and they emitted PSL with the peak located at 615 nm.The result also indicated that some co-doped rare earth ions could increase fluorescence intensities of the traditional electron trapping materials SrS：Eu2＋.展开更多
It is assumed from the energy level that ultraviolet (UV) photons may have intensifying effect on BaFBr∶Eu 2+. In this paper, effect of UV photons (220～290 nm) on the PSL intensity of X-ray irradiated BaFBr∶Eu 2+...It is assumed from the energy level that ultraviolet (UV) photons may have intensifying effect on BaFBr∶Eu 2+. In this paper, effect of UV photons (220～290 nm) on the PSL intensity of X-ray irradiated BaFBr∶Eu 2+ was measured and compared to that on the PSL intensity of 220 nm photons irradiated BaFBr∶Eu 2+. It was found that after the excitation of UV photons the PSL intensity of X-ray irradiated samples decreases least at 250 nm and that of 220 nm photons irradiated samples increases most at 250 nm. When the irradiation sources are X-rays and 220 nm photons the excited electrons are photoelectron and thermal-electrons, respectively, and they have different possibility of being captured by electron traps or combined with luminescent centers. And the peak at 250 nm can be explained with the model of electrons tunneling. It is assumed that the electrons excited by 250 nm have the most possibility of tunneling.展开更多
Before and after X-irradiation, two photon spectral hole burning experiments in BaF (Cl,Br) : Sm2+ were performed by a 560 nm laser light at liquid nitrogen temperature. The results show that spectral hole burning of ...Before and after X-irradiation, two photon spectral hole burning experiments in BaF (Cl,Br) : Sm2+ were performed by a 560 nm laser light at liquid nitrogen temperature. The results show that spectral hole burning of Sm2+ doped fluoride halide mixed crystals are accompanied by photostimulated luminescence process. This process make hole burning efficiency decreased.展开更多
采用原位聚合法制备了PI/TiO_2和PI/SiO_2纳米复合薄膜。研究质量分数均为10%的两种纳米掺杂对PI复合薄膜介电性能的影响,采用光刺激放电电流法(PSD)表征两种纳米颗粒对PI复合薄膜陷阱能级的影响,通过陷阱理论对介电性能的影响机制进行...采用原位聚合法制备了PI/TiO_2和PI/SiO_2纳米复合薄膜。研究质量分数均为10%的两种纳米掺杂对PI复合薄膜介电性能的影响,采用光刺激放电电流法(PSD)表征两种纳米颗粒对PI复合薄膜陷阱能级的影响,通过陷阱理论对介电性能的影响机制进行探讨。结果表明:TiO_2和SiO_2纳米掺杂提高了PI的电导率和介电常数,介质损耗相应增加,耐电晕寿命明显提高,电气强度虽有所下降但仍满足实际需要。两种纳米掺杂都在PI基体中引入了大量的浅陷阱,PI/TiO_2和PI/SiO_2复合薄膜的陷阱能级范围分别为1.83~2.85 e V和2.13~2.83e V,且SiO_2纳米颗粒引入的浅陷阱密度低于TiO_2纳米颗粒。在此基础上,通过陷阱理论分析了两种复合薄膜的耐电晕老化机制。展开更多
文摘The CaS∶Eu^(2+), Sm^(3+) powders were prepared by high-temperature solid method in a reducing atmosphere. The influences of temperature and fired-time on properties of samples were studied. XRD analysis shows that crystal structure of CaS has formed at 700 ℃. Spectrum analysis results show that the samples which were stimulated by 980 nm laser after excited by ultraviolet lamp emit red luminescence peaking at 649 nm.
基金Project supported by the National Natural Science Foundation of China(61565009,11664022,11804038)the Foundation of Natural Science of Yunnan Province(2016FB088)+3 种基金the Reserve Talents Project of Yunnan Province(2017HB011)the Young Talents Support Program of Faculty of Materials Science and Engineering,Kunming University of Science and Technology(14078342)Chongqing Natural Science Foundation(cstc2017jcyjAX0418,cstc2018jcyjAX0569)Foundation of Chongqing University of Arts and Sciences(R2016DQ10)
文摘Photo-stimulated luminescence(PSL) is the process in which trapped charges are released by photons and produce luminescence through recombination. The variegated optical characteristics of photostimulated phosphors(PSPs) have drawn increasing attention and a large body of work encompassing mechanism and application of PSPs has been addressed. The optical data storage capacity resulting from abundant defect states enables PSPs to be applied to information storage. Moreover, PSPs provide potential application for anti-counterfeiting, as color changes due to the tunneling process. Recently, near infrared(NIR) light PSPs have been developed, exhibiting enormous potential for in vivo bio-imaging, as the stable and high noise-signal ratio characteristic of PSL. In this review, we devote to introducing the development and process of PSPs, and the challenge and future advance have also been demonstrated.
基金supported by the National Natural Science Foundation of China(52172277,21936004)the Pearl River Talent Plan of Guangdong Province of China(2107GC010344)
文摘X-ray activated near-infrared(NIR)persistent luminescence has promising application in biomedical luminous imaging.However,there are strict medical restrictions on X-ray dosage to avoid radiation disease.There is a need to develop a simple strategy to improve persistent luminescence imaging quality using low-dose X-ray.NIR photo-stimulation can enhance the persistent luminescence intensity by transporting the stored energy from deep traps to shallow ones,so that enhanced upconversion-like NIR-to-NIR persistent luminescence imaging can be conducted after low-dose X-ray excitation.However,existing NIR persistent luminescence phosphors have limited absorption in the NIR.To realize optimized NIR photostimulation,Nd^(3+)is proposed as a potential sensitizer to enhance the absorption of persistent luminescence phosphor to 808 nm light.In this study,ZnGa_(2)O_(4):Sn_(0.1),Cr_(0.003),Nd_(0.01)(ZGSC-Nd)was synthesized with a persistent luminescence peak at~700 nm.After activation with 1 Gy of X-ray,its persistent luminescence attenuated to less than 5%of its original intensity after 2800 s.Interestingly,the nearly vanished persistent luminescence was enhanced 5 times after 808 nm photo-stimulation,which was assigned to Nd absorption.Thus,a pseudo-upconverted persistent luminescence from 808 to 700 nm was realized more efficiently.A Nd-sensitized NIR photo-stimulated persistent luminescence mechanism was proposed.This phenomenon was applied for improved luminous imaging of ZGSC-Nd labeled bone cement after a single low-dose X-ray imaging.This work provides an applicable strategy to realize better persistent luminescence imaging after low-dose X-ray activation and will be significant on designing X-ray activated persistent phosphors for biomedical application.
基金Project supported by the National Natural Science Foundations of China (20876002, 20976002)the Beijing Natural Science Foundation (2091002)Funding Project for Academic Human Resources Development in Institutions of Higher Learning under the Jurisdiction of Beijing Municipality
文摘Trivalent rare-earth ions （La3＋,Pr3＋,Nd3＋,Sm3＋,Gd3＋,Tb3＋,Dy3＋,Ho3＋,Er3＋,Tm3＋,and Yb3＋） were investigated as the codoped auxiliary sensitizer for the electron trapping materials SrS：Eu2＋ in order to enhance the fluorescence properties.It was found that Sm3＋ and Tb3＋ had the best photoluminescence stimulated luminescence （PSL） effect among the selected trivalent rare-earth ions.All the SrS：Eu2＋ samples doped by different trivalent rare-earth ions could be stimulated by 980 nm laser after being exposed to the conventional sunlight,and they emitted PSL with the peak located at 615 nm.The result also indicated that some co-doped rare earth ions could increase fluorescence intensities of the traditional electron trapping materials SrS：Eu2＋.
文摘It is assumed from the energy level that ultraviolet (UV) photons may have intensifying effect on BaFBr∶Eu 2+. In this paper, effect of UV photons (220～290 nm) on the PSL intensity of X-ray irradiated BaFBr∶Eu 2+ was measured and compared to that on the PSL intensity of 220 nm photons irradiated BaFBr∶Eu 2+. It was found that after the excitation of UV photons the PSL intensity of X-ray irradiated samples decreases least at 250 nm and that of 220 nm photons irradiated samples increases most at 250 nm. When the irradiation sources are X-rays and 220 nm photons the excited electrons are photoelectron and thermal-electrons, respectively, and they have different possibility of being captured by electron traps or combined with luminescent centers. And the peak at 250 nm can be explained with the model of electrons tunneling. It is assumed that the electrons excited by 250 nm have the most possibility of tunneling.
文摘Before and after X-irradiation, two photon spectral hole burning experiments in BaF (Cl,Br) : Sm2+ were performed by a 560 nm laser light at liquid nitrogen temperature. The results show that spectral hole burning of Sm2+ doped fluoride halide mixed crystals are accompanied by photostimulated luminescence process. This process make hole burning efficiency decreased.
文摘采用原位聚合法制备了PI/TiO_2和PI/SiO_2纳米复合薄膜。研究质量分数均为10%的两种纳米掺杂对PI复合薄膜介电性能的影响,采用光刺激放电电流法(PSD)表征两种纳米颗粒对PI复合薄膜陷阱能级的影响,通过陷阱理论对介电性能的影响机制进行探讨。结果表明:TiO_2和SiO_2纳米掺杂提高了PI的电导率和介电常数,介质损耗相应增加,耐电晕寿命明显提高,电气强度虽有所下降但仍满足实际需要。两种纳米掺杂都在PI基体中引入了大量的浅陷阱,PI/TiO_2和PI/SiO_2复合薄膜的陷阱能级范围分别为1.83~2.85 e V和2.13~2.83e V,且SiO_2纳米颗粒引入的浅陷阱密度低于TiO_2纳米颗粒。在此基础上,通过陷阱理论分析了两种复合薄膜的耐电晕老化机制。
