In this study,the regulation of Al^(3+)/Ga^(3+) on Sr_(2)(Ga,Al)_(2)SiO_(7):Ce^(3+)phosphors is demonstrated to enhance the photoluminescence and persistent luminescence(PersL)performances of Ce^(3+).With the replacem...In this study,the regulation of Al^(3+)/Ga^(3+) on Sr_(2)(Ga,Al)_(2)SiO_(7):Ce^(3+)phosphors is demonstrated to enhance the photoluminescence and persistent luminescence(PersL)performances of Ce^(3+).With the replacement of Al^(3+),the emission band of Ce^(3+) shifts to the longer wavelength side,thermal stability of Ce^(3+) emission becomes better,and Ce^(3+) persistent luminescence shows stronger intensity and longer lifetime.To get insight into the structure-luminescence relationship,the influences of Al^(3+)/Ga^(3+) on the structure of Sr_(2)(Ga,Al)_(2)SiO_(7):Ce^(3+),4f–5d_(i)(i=1–5)transition energies of Ce^(3+) and trap d_(i)stributions are d_(i) scussed.With the construction of the vacuum referred bind_(i)ng energy scheme and analysis of a series of thermoluminescence(TL)spectra,the increase of band gap is found to tune the trap depths and change persistent luminescence performances of Ce^(3+) in Sr_(2)(Ga,Al)_(2)SiO_(7).Finally,with the stimulation of a 1060 nm laser,the optimized Sr_(2)(Ga,Al)_(2)SiO_(7):Ce^(3+) phosphors show strong persistent luminescence of Ce^(3+),suggesting the potential for application in optical storage.展开更多
Persistent luminescence(PersL)materials,especially sunlight excitable warm color(550-660 nm)PersL materials,have great practical value in information storage,emergency lighting and displays,and in vivo alternating cur...Persistent luminescence(PersL)materials,especially sunlight excitable warm color(550-660 nm)PersL materials,have great practical value in information storage,emergency lighting and displays,and in vivo alternating current LED lamps.But up to now,designing and developing efficient sunlight-activated warm color PersL materials has faced huge challenges.展开更多
The advent of alternating current light-emitting diodes(AC-LEDs)based on persistent luminescence(PersL)phosphors is a major breakthrough in terms of long service lifetime,reduced production cost,and high energy utiliz...The advent of alternating current light-emitting diodes(AC-LEDs)based on persistent luminescence(PersL)phosphors is a major breakthrough in terms of long service lifetime,reduced production cost,and high energy utilization efficiency.However,the efficiency of the current PersL based AC-LEDs for flicker reduction in each AC cycle needs to be improved.To address this issue,herein,we develop a series of green-emitting persistent luminescence(PersL)phosphors BaY_(2)Al_(2)Ga_(2)SiO_(12):Ce^(3+),Bi^(3+)(BYAGSO:Ce^(3+),Bi^(3+))via a defect engineering approach,whose PersL can be efficiently activated by blue-light.A strategy that introduces bismuth with multivalent states into BYAGSO:0.04Ce^(3+)is proposed to optimize the PersL intensity.Theτ80 value(the time when the PersL intensity reaches 80%of its initial value)of BYAGSO:0.04Ce^(3+),0.01Bi^(3+)is about 30 ms,which demonstrates its effectiveness in minimizing flicker from AC-LEDs.Meanwhile,with the aid of excitation temperature-dependent and fading thermoluminescence(TL)experiments,the trapping levels related to Bi^(3+)in BYAGSO:Ce^(3+),Bi^(3+)are also investigated through the initial rise method.Furthermore,we fabricate an AC-LED device using the phosphor BYAGSO:0.04Ce^(3+),0.01Bi^(3+)and the commercial red PersL phosphor Sr_(0.75)Ca_(0.25)S:Eu^(2+)(SCS:Eu^(2+))with an InGaN blue-emitting chip,which shows warm-white emission with a reduced percent flicker of 47.06%.These results demonstrate that the BYAGSO:Ce^(3+),Bi^(3+)phosphor might be a promising candidate for lowflicker AC-LEDs.展开更多
Ultraviolet(UV)emitting persistent luminescence(PersL)materials have aroused significant interest,owing to their unique self-illuminating high-photo-energy feature under excitation-free conditions.In particular,the ad...Ultraviolet(UV)emitting persistent luminescence(PersL)materials have aroused significant interest,owing to their unique self-illuminating high-photo-energy feature under excitation-free conditions.In particular,the advent of X-rays as a charging source for UV PersL has facilitated the control of PersL properties and triggered a breakthrough in possible applications such as X-ray imaging techniques,phototherapy,photocatalysis,and optical information storage.Here,we present novel PersL materials that exhibit ultra-long UV emission for over 2000 h,as detected with a spectrometer.Experimental characterization revealed that the intrinsic oxygen vacancies associated with the local structure of the perovskite LaGaO_(3) can function as traps,which have super capabilities in energy collection and storage triggered by X-ray irradiation.Notably,this design concept is guided by utilizing an oxygen-defect perovskite as a host,which can serve as powerful guidance for expediting the discovery of new PersL materials.Moreover,due to excellent UV PersL performances,the proposed photodynamic therapy(PDT)platform LaGaO_(3):Bi,Sb@g-C3N4 demonstrates excellent PDT efficiency in vivo using low-dose X-ray irradiation.Our discovery of this UV PersL material is expected to provide directional solutions and novel perspectives for the development and application of UV luminescence technology.展开更多
基金the National Natural Science Foundation of China(Grant No.61905289 and 51902053)Natural Science Foundation of Guangdong Province(Grant No.2019A1515011988)+1 种基金Young Innovative Talents Project of Guangdong Provincial(No.2020KQNCX242)the Innovative Team Program of Guangdong Province(No.2020KCXTD057).
文摘In this study,the regulation of Al^(3+)/Ga^(3+) on Sr_(2)(Ga,Al)_(2)SiO_(7):Ce^(3+)phosphors is demonstrated to enhance the photoluminescence and persistent luminescence(PersL)performances of Ce^(3+).With the replacement of Al^(3+),the emission band of Ce^(3+) shifts to the longer wavelength side,thermal stability of Ce^(3+) emission becomes better,and Ce^(3+) persistent luminescence shows stronger intensity and longer lifetime.To get insight into the structure-luminescence relationship,the influences of Al^(3+)/Ga^(3+) on the structure of Sr_(2)(Ga,Al)_(2)SiO_(7):Ce^(3+),4f–5d_(i)(i=1–5)transition energies of Ce^(3+) and trap d_(i)stributions are d_(i) scussed.With the construction of the vacuum referred bind_(i)ng energy scheme and analysis of a series of thermoluminescence(TL)spectra,the increase of band gap is found to tune the trap depths and change persistent luminescence performances of Ce^(3+) in Sr_(2)(Ga,Al)_(2)SiO_(7).Finally,with the stimulation of a 1060 nm laser,the optimized Sr_(2)(Ga,Al)_(2)SiO_(7):Ce^(3+) phosphors show strong persistent luminescence of Ce^(3+),suggesting the potential for application in optical storage.
基金supported by the National Key R&D Program of China(Grant No.2019YFA0709101)the National Natural Science Foundation of China(Grant No.52072364)the Key Research Program of the Chinese Academy of Sciences(Grant No.ZDRW-CN-2021-3-3-06).
文摘Persistent luminescence(PersL)materials,especially sunlight excitable warm color(550-660 nm)PersL materials,have great practical value in information storage,emergency lighting and displays,and in vivo alternating current LED lamps.But up to now,designing and developing efficient sunlight-activated warm color PersL materials has faced huge challenges.
基金financially supported by the National Key R&D Program of China(Grant No.2019YFA0709101)the Key Research Program of the Chinese Academy of Sciences(Grant No.ZDRW-CN-2021-3-3-06)the National Natural Science Foundation of China(Grant No.52072364,51902305,22175169)。
文摘The advent of alternating current light-emitting diodes(AC-LEDs)based on persistent luminescence(PersL)phosphors is a major breakthrough in terms of long service lifetime,reduced production cost,and high energy utilization efficiency.However,the efficiency of the current PersL based AC-LEDs for flicker reduction in each AC cycle needs to be improved.To address this issue,herein,we develop a series of green-emitting persistent luminescence(PersL)phosphors BaY_(2)Al_(2)Ga_(2)SiO_(12):Ce^(3+),Bi^(3+)(BYAGSO:Ce^(3+),Bi^(3+))via a defect engineering approach,whose PersL can be efficiently activated by blue-light.A strategy that introduces bismuth with multivalent states into BYAGSO:0.04Ce^(3+)is proposed to optimize the PersL intensity.Theτ80 value(the time when the PersL intensity reaches 80%of its initial value)of BYAGSO:0.04Ce^(3+),0.01Bi^(3+)is about 30 ms,which demonstrates its effectiveness in minimizing flicker from AC-LEDs.Meanwhile,with the aid of excitation temperature-dependent and fading thermoluminescence(TL)experiments,the trapping levels related to Bi^(3+)in BYAGSO:Ce^(3+),Bi^(3+)are also investigated through the initial rise method.Furthermore,we fabricate an AC-LED device using the phosphor BYAGSO:0.04Ce^(3+),0.01Bi^(3+)and the commercial red PersL phosphor Sr_(0.75)Ca_(0.25)S:Eu^(2+)(SCS:Eu^(2+))with an InGaN blue-emitting chip,which shows warm-white emission with a reduced percent flicker of 47.06%.These results demonstrate that the BYAGSO:Ce^(3+),Bi^(3+)phosphor might be a promising candidate for lowflicker AC-LEDs.
基金the Foshan Science and Technology Bureau(Foshan Science and Technology Innovation Project,1920001000150-08)the National Natural Science Foundation of China(52102195)+2 种基金the Joint Funds of the National Natural Science Foundation of China and Yunnan Province(U1902222)the Guangdong Provincial Science&Technology Project(2022A0505050032)the Major Science and Technology Research and Development Project of Jiangxi Province(20223AAE01003)for the financial support。
文摘Ultraviolet(UV)emitting persistent luminescence(PersL)materials have aroused significant interest,owing to their unique self-illuminating high-photo-energy feature under excitation-free conditions.In particular,the advent of X-rays as a charging source for UV PersL has facilitated the control of PersL properties and triggered a breakthrough in possible applications such as X-ray imaging techniques,phototherapy,photocatalysis,and optical information storage.Here,we present novel PersL materials that exhibit ultra-long UV emission for over 2000 h,as detected with a spectrometer.Experimental characterization revealed that the intrinsic oxygen vacancies associated with the local structure of the perovskite LaGaO_(3) can function as traps,which have super capabilities in energy collection and storage triggered by X-ray irradiation.Notably,this design concept is guided by utilizing an oxygen-defect perovskite as a host,which can serve as powerful guidance for expediting the discovery of new PersL materials.Moreover,due to excellent UV PersL performances,the proposed photodynamic therapy(PDT)platform LaGaO_(3):Bi,Sb@g-C3N4 demonstrates excellent PDT efficiency in vivo using low-dose X-ray irradiation.Our discovery of this UV PersL material is expected to provide directional solutions and novel perspectives for the development and application of UV luminescence technology.
