In order to obtain a single-host white-light phosphor, a series of KCaPO4 powder samples tri-doped with Eu2＋, Tb3＋ and Mn2＋ were synthesized via high-temperature solid-state reaction method. Their structural and lu...In order to obtain a single-host white-light phosphor, a series of KCaPO4 powder samples tri-doped with Eu2＋, Tb3＋ and Mn2＋ were synthesized via high-temperature solid-state reaction method. Their structural and luminescence properties were investigated. Under proper ultraviolet excitation （255-405 urn）, white light was obtained, consisting of blue, green and red emissions stemming from Eu2＋, Th3＋, Mn2＋ ions respectively. The temperature stability of our sample was analyzed by studying the variation tendeney of CIE chromaticity coordinates at different temperatures. The results indicated that this phosphor could yield good color stability when utilized in WLED.展开更多
A new europium complex Eu(tta)_(3)Li(la)based on 1,10-phenanthroline derivative(Li=(2-(3,5-dimethoxyphenyl)-1 H-imidazo[4,5-f][1,10]phenanthroline),tta=2-thenoyItrifluoroacetone)was designed and synthesized.Its struct...A new europium complex Eu(tta)_(3)Li(la)based on 1,10-phenanthroline derivative(Li=(2-(3,5-dimethoxyphenyl)-1 H-imidazo[4,5-f][1,10]phenanthroline),tta=2-thenoyItrifluoroacetone)was designed and synthesized.Its structure was characterized by^(1)H and^(13)C NMR,elemental analysis,UV-vis,fluorescence spectra and single crystal X-ray diffraction.The crystal of the complex la belongs to monoclinic system with the space group P2_(1/n).The europium complex la in the solid and in the solution displays the typical emission of Eu(III)ion centered at 612 nm as a result of the electric dipole transition(^(5)D_(0)-►^(7)F_(2)).It exhibits high quantum yield(20.42%),long lifetime(0.29 ms)and good CIE color coordinate(0.67,0.33)in solid.In addition,the complex shows high sensitivity and selectivity towards Al^(3+)and Zn^(2+)in methanol solution which can be attributed to the Al^(3+)/Zn^(2+)cation instead of Eu^(3+)in the complex la.The LODs for Al^(3+)and Zn^(2+)were calculated to be 5.880×10^(-7)and 7.678×10^(-8)mol/L,respectively.Besides,the additions of Al^(3+)and Zn^(2+)express remarkable color changes from red to bright blue and ivory that can be clearly observed by the naked eye respectively.展开更多
The synthesis, composition optimization, VUV Photoluminescence (PL) spectra, and optical properties, of (Y,Gd)(V,P)O4∶Eu3+ phosphors were investigated by synchrotron radiation. The VUV PLE spectra and the correlation...The synthesis, composition optimization, VUV Photoluminescence (PL) spectra, and optical properties, of (Y,Gd)(V,P)O4∶Eu3+ phosphors were investigated by synchrotron radiation. The VUV PLE spectra and the correlation among VUV PL intensity, λem, and Eu3+, Gd3+, and P-content were established. The PLE spectral studies showed that (Y,Gd)(V,P)O4∶Eu3+ exhibited significant absorption in the VUV range. The VUV PL intensity was found to enhance with PO43- and Gd3+-doping. Furthermore, the chromaticity characteristics of (Y,Gd)(V,P)O4∶Eu3+ were also found to be (0.6614, 0.3286) and compared against (Y, Gd)BO3∶Eu3+ as a reference. Based on the characterization results, we are currently improving and evaluating the potential application of (Y,Gd)(V,P)O4∶Eu3+ as a new red-emitting PDP phosphor.展开更多
In an effort to develop new green-emitting PDP phosphors with high efficiency, investigated were the synthesis, VUV photoluminescence (PL) spectra, optical properties, and chromaticity of Ca(La1-x-yTbxGdy. )4Si3O13 ph...In an effort to develop new green-emitting PDP phosphors with high efficiency, investigated were the synthesis, VUV photoluminescence (PL) spectra, optical properties, and chromaticity of Ca(La1-x-yTbxGdy. )4Si3O13 phosphors by using synchrotron radiation. Upon analysis of the VUV spectroscopic and chromaticity investigations on the new greenemitting VUV phosphors, were an optimized composition achieved. The PLE spectral studies show that Ca ( La1-x-y TbxGdy)4Si3O13 exhibit significant absorption in the VUV range. The VUV PL intensity was found to enhance with Gd3+-doping. Furthermore, the 1931 CIE chromaticity coordinates of Ca(La,Gd)4Si3O13:Tb were found to be (0.286, 0.548), as compared to (0.230, 0.712) for Zn2SiP4:Mn2+ as a reference. The potential application of Ca(La,Gd)4Si3O13:Tb as a new green-emitting PDP phosphor are being currently improving and evaluating.展开更多
The main difficulties hindering development of a deep-blue phosphorescent cyclometalated Ir(III)complex are insufficient colour purity,i.e.,failure to achieve ideal Commission Internationale de L’Eclairage(CIE)coordi...The main difficulties hindering development of a deep-blue phosphorescent cyclometalated Ir(III)complex are insufficient colour purity,i.e.,failure to achieve ideal Commission Internationale de L’Eclairage(CIE)coordinates of(0.14,0.09),and insufficient emission efficiency and stability.The latter problem is due to the highly energetic and hot excited states of these complexes,which yield faster decomposition.Therefore,control of the excited-state properties of cyclometalated Ir(III)complexes through systematic chemical modification of the ligands is being extensively investigated,with the aim of developing efficient and stable blue phosphorescent materials.The most common strategies towards achievement of a blue phosphorescent cyclometalated Ir(III)complex involve(1)substitution of electronwithdrawing F atoms at the cyclometalating ligands that stabilise the HOMO orbitals and(2)use of a heteroleptic system with electron-rich ancillary ligands bearing a 5-membered ring heterocycle to increase the LUMO energy level.However,the C-F bonds on the cyclometalating ligands have been found to be inherently unstable during device operation;thus,other types of electron-withdrawing groups(e.g.,the cyano,trifluoromethyl,and sulfonyl groups)have been applied.Along with phosphorescence colour tuning to blue,the influence of the ligand structure on the photoluminescence quantum yield(PLQY)is also being intensively investigated.Two major PLQY lowering mechanisms for blue emissive Ir(III)complexes have been identified:(1)the vibronic-coupled non-radiative decay process and(2)crossing from the emissive state to an upper non-emissive ^(3)MC excited state.To enhance the PLQY,mechanism(1)can be suppressed by employing rigid ligand frameworks to restrict intramolecular motion,whereas mechanism(2)can be prevented by destabilising the ^(3)MC state using strongσdonor ligands such as N-heterocyclic carbenes.This review summarises the fundamental photophysics of cyclometalated Ir(III)complexes and surveys design strategies for efficient blue phosphorescent Ir(III)complexes,to provide a guide for future research in this field.展开更多
Recent progress in the field of carbon dots(CDs)has highlighted their significant potential,attributed to their exceptional optical properties and diverse applications,most notably in the realm of white lightemitting ...Recent progress in the field of carbon dots(CDs)has highlighted their significant potential,attributed to their exceptional optical properties and diverse applications,most notably in the realm of white lightemitting diodes(WLEDs).CDs are recognized for their broad spectrum of emission,adjustable fluorescence,and excellent thermal stability,making them ideal candidates for use in WLEDs.However,the challenge lies in synthesizing CDs that can emit long-wavelength,multicolor light from a single host material.This research presents a highly efficient dual-core-shell structured white-emitting phosphor,denoted as ZnS:Mn-CDs@SiO_(2),which has achieved an impressive photoluminescence quantum yield(PLQY)of 25.8%and an expansive full width at half maximum(FWHM)of 131 nm.The successful implementation of this novel material has led to the creation of WLEDs with Commission Internationale de l’Eclairage(CIE)coordinates at(0.32,0.38)and a correlated color temperature(CCT)of 5854.3 K,marking a significant stride in the development of high-performance WLEDs.展开更多
基金supported by National Key Basic Research Program of China(2013CB921800)the National Natural Science Foundation of China(11374291,11204292,11274299,11311120047)+1 种基金the Fundamental Research Funds for the Central Universities(WK2030020021)Anhui Provincial Natural Science Foundation(1308085QE75)
文摘In order to obtain a single-host white-light phosphor, a series of KCaPO4 powder samples tri-doped with Eu2＋, Tb3＋ and Mn2＋ were synthesized via high-temperature solid-state reaction method. Their structural and luminescence properties were investigated. Under proper ultraviolet excitation （255-405 urn）, white light was obtained, consisting of blue, green and red emissions stemming from Eu2＋, Th3＋, Mn2＋ ions respectively. The temperature stability of our sample was analyzed by studying the variation tendeney of CIE chromaticity coordinates at different temperatures. The results indicated that this phosphor could yield good color stability when utilized in WLED.
基金Project supported by the National Natural Science Foundation of China.China(21861017,41867053)the Key Project of Natural Science Foundation of Jiangxi Province,China(20192ACBL20011).
文摘A new europium complex Eu(tta)_(3)Li(la)based on 1,10-phenanthroline derivative(Li=(2-(3,5-dimethoxyphenyl)-1 H-imidazo[4,5-f][1,10]phenanthroline),tta=2-thenoyItrifluoroacetone)was designed and synthesized.Its structure was characterized by^(1)H and^(13)C NMR,elemental analysis,UV-vis,fluorescence spectra and single crystal X-ray diffraction.The crystal of the complex la belongs to monoclinic system with the space group P2_(1/n).The europium complex la in the solid and in the solution displays the typical emission of Eu(III)ion centered at 612 nm as a result of the electric dipole transition(^(5)D_(0)-►^(7)F_(2)).It exhibits high quantum yield(20.42%),long lifetime(0.29 ms)and good CIE color coordinate(0.67,0.33)in solid.In addition,the complex shows high sensitivity and selectivity towards Al^(3+)and Zn^(2+)in methanol solution which can be attributed to the Al^(3+)/Zn^(2+)cation instead of Eu^(3+)in the complex la.The LODs for Al^(3+)and Zn^(2+)were calculated to be 5.880×10^(-7)and 7.678×10^(-8)mol/L,respectively.Besides,the additions of Al^(3+)and Zn^(2+)express remarkable color changes from red to bright blue and ivory that can be clearly observed by the naked eye respectively.
基金the National Science Council of Taiwan (NSC95 -2113-M-009-024-MY3)
文摘The synthesis, composition optimization, VUV Photoluminescence (PL) spectra, and optical properties, of (Y,Gd)(V,P)O4∶Eu3+ phosphors were investigated by synchrotron radiation. The VUV PLE spectra and the correlation among VUV PL intensity, λem, and Eu3+, Gd3+, and P-content were established. The PLE spectral studies showed that (Y,Gd)(V,P)O4∶Eu3+ exhibited significant absorption in the VUV range. The VUV PL intensity was found to enhance with PO43- and Gd3+-doping. Furthermore, the chromaticity characteristics of (Y,Gd)(V,P)O4∶Eu3+ were also found to be (0.6614, 0.3286) and compared against (Y, Gd)BO3∶Eu3+ as a reference. Based on the characterization results, we are currently improving and evaluating the potential application of (Y,Gd)(V,P)O4∶Eu3+ as a new red-emitting PDP phosphor.
基金Project supported by National Science Council of Taiwan, R.O.C. (NSC94-2113-M-009-001)
文摘In an effort to develop new green-emitting PDP phosphors with high efficiency, investigated were the synthesis, VUV photoluminescence (PL) spectra, optical properties, and chromaticity of Ca(La1-x-yTbxGdy. )4Si3O13 phosphors by using synchrotron radiation. Upon analysis of the VUV spectroscopic and chromaticity investigations on the new greenemitting VUV phosphors, were an optimized composition achieved. The PLE spectral studies show that Ca ( La1-x-y TbxGdy)4Si3O13 exhibit significant absorption in the VUV range. The VUV PL intensity was found to enhance with Gd3+-doping. Furthermore, the 1931 CIE chromaticity coordinates of Ca(La,Gd)4Si3O13:Tb were found to be (0.286, 0.548), as compared to (0.230, 0.712) for Zn2SiP4:Mn2+ as a reference. The potential application of Ca(La,Gd)4Si3O13:Tb as a new green-emitting PDP phosphor are being currently improving and evaluating.
基金supported by the National Research Foundation of Korea(2019R1F1A1058578).
文摘The main difficulties hindering development of a deep-blue phosphorescent cyclometalated Ir(III)complex are insufficient colour purity,i.e.,failure to achieve ideal Commission Internationale de L’Eclairage(CIE)coordinates of(0.14,0.09),and insufficient emission efficiency and stability.The latter problem is due to the highly energetic and hot excited states of these complexes,which yield faster decomposition.Therefore,control of the excited-state properties of cyclometalated Ir(III)complexes through systematic chemical modification of the ligands is being extensively investigated,with the aim of developing efficient and stable blue phosphorescent materials.The most common strategies towards achievement of a blue phosphorescent cyclometalated Ir(III)complex involve(1)substitution of electronwithdrawing F atoms at the cyclometalating ligands that stabilise the HOMO orbitals and(2)use of a heteroleptic system with electron-rich ancillary ligands bearing a 5-membered ring heterocycle to increase the LUMO energy level.However,the C-F bonds on the cyclometalating ligands have been found to be inherently unstable during device operation;thus,other types of electron-withdrawing groups(e.g.,the cyano,trifluoromethyl,and sulfonyl groups)have been applied.Along with phosphorescence colour tuning to blue,the influence of the ligand structure on the photoluminescence quantum yield(PLQY)is also being intensively investigated.Two major PLQY lowering mechanisms for blue emissive Ir(III)complexes have been identified:(1)the vibronic-coupled non-radiative decay process and(2)crossing from the emissive state to an upper non-emissive ^(3)MC excited state.To enhance the PLQY,mechanism(1)can be suppressed by employing rigid ligand frameworks to restrict intramolecular motion,whereas mechanism(2)can be prevented by destabilising the ^(3)MC state using strongσdonor ligands such as N-heterocyclic carbenes.This review summarises the fundamental photophysics of cyclometalated Ir(III)complexes and surveys design strategies for efficient blue phosphorescent Ir(III)complexes,to provide a guide for future research in this field.
基金the Recruitment Program of Global Experts,National Natural Science Foundation of China(Grant No.62175033 and 61775040)the Fujian Science&Technology Innovation Laboratory for Optoelectronic Information(Grant No.2021ZZ126)Fuzhou University for the financial support.
文摘Recent progress in the field of carbon dots(CDs)has highlighted their significant potential,attributed to their exceptional optical properties and diverse applications,most notably in the realm of white lightemitting diodes(WLEDs).CDs are recognized for their broad spectrum of emission,adjustable fluorescence,and excellent thermal stability,making them ideal candidates for use in WLEDs.However,the challenge lies in synthesizing CDs that can emit long-wavelength,multicolor light from a single host material.This research presents a highly efficient dual-core-shell structured white-emitting phosphor,denoted as ZnS:Mn-CDs@SiO_(2),which has achieved an impressive photoluminescence quantum yield(PLQY)of 25.8%and an expansive full width at half maximum(FWHM)of 131 nm.The successful implementation of this novel material has led to the creation of WLEDs with Commission Internationale de l’Eclairage(CIE)coordinates at(0.32,0.38)and a correlated color temperature(CCT)of 5854.3 K,marking a significant stride in the development of high-performance WLEDs.
