Single-walled carbon nanotubes （SWCNTs） illuminated by white light should appear colored due to resonance Rayleigh scattering. However, true-color imaging of SWCNTs on substrates has not been reported, because of th...Single-walled carbon nanotubes （SWCNTs） illuminated by white light should appear colored due to resonance Rayleigh scattering. However, true-color imaging of SWCNTs on substrates has not been reported, because of the extremely low scattering intensity of SWCNTs and the strong substrate scattering. Here we show that Rayleigh scattering can be greatly enhanced by the interface dipole enhancement effect. Consequently colorful SWCNTs on substrates can be directly imaged under an optical microscope by wide field supercontinuum laser illumination, which facilitates high throughput chirality assignment of individual SWCNTs. This approach, termed ＂Rayleigh imaging microscopy＂, is not restricted to SWCNTs, but widely applicable to a variety of nanomaterials, which enables the colorful nanoworld to be explored under optical microscopes.展开更多
The development of single-component white emitters for white light-emitting diodes(WLEDs)remains challenging.Herein,a rare earth-free white light-emitting composite is developed by assembling blue-emitting carbon dots...The development of single-component white emitters for white light-emitting diodes(WLEDs)remains challenging.Herein,a rare earth-free white light-emitting composite is developed by assembling blue-emitting carbon dots(CDs)and yellow-emitting Cs_(2)InCl_(5)·H_(2)O:Sb^(3+)metal halide crystals via a facile liquid-liquid diffusion-assisted crystallization approach.The encapsulation mechanism is then analyzed.Depending on the ratios of blue/yellow emitters,these luminescent composites exhibit white light emission with tunable cold and warm hues.The composites also possess prominent ultraviolet resistance,thermal tolerance,and good stability at about 200°C.By employing such“CDs in metal halide”composites as a converter,a WLED is successfully fabricated with a high color rendering index of 93.6,benefiting from the assembled blue and yellow broadband emission.With this strategy,the developed composites show great promise in next-generation WLED lighting.展开更多
SrZn2(PO4)2:Sm3+ phosphor was synthesized by a high temperature solid-state reaction in atmosphere. SrZn2(PO4)2:Sm3+ phosphor is efficiently excited by ultraviolet(UV) and blue light, and the emission peaks are assign...SrZn2(PO4)2:Sm3+ phosphor was synthesized by a high temperature solid-state reaction in atmosphere. SrZn2(PO4)2:Sm3+ phosphor is efficiently excited by ultraviolet(UV) and blue light, and the emission peaks are assigned to the transitions of 4G5/2-6H5/2(563 nm), 4G5/2-6H7/2(597 nm and 605 nm) and 4G5/2-6H9/2(644 nm and 653 nm). The emission intensities of SrZn2(PO4)2:Sm3+ are influenced by Sm3+ concentration, and the concentration quenching effect of SrZn2(PO4)2:Sm3+ is also observed. When doping A+(A=Li, Na and K) ions, the emission intensity of SrZn2(PO4)2:Sm3+ can be obviously enhanced. The Commission Internationale de l'Eclairage(CIE) color coordinates of SrZn2(PO4)2:Sm3+ locate in the orange-red region. The results indicate that the phosphor has a potential application in white light emitting diodes(LEDs).展开更多
A kind of efficient non-doped white organic light-emitting diodes(WOLEDs) were realized by using a bright blue-emitting layer of 4,4-bis(2,2-diphenylvinyl)-1,1-biphenyl(DPVBi) combining with red emitting ultrathin lay...A kind of efficient non-doped white organic light-emitting diodes(WOLEDs) were realized by using a bright blue-emitting layer of 4,4-bis(2,2-diphenylvinyl)-1,1-biphenyl(DPVBi) combining with red emitting ultrathin layer of [2-methyl-6-[2-(2,3,6,7-tetrahydro-1H,5H-benzo[ij]quinolizin-9-yl)ethenyl]-4H-pyran-4-ylidene]propane-dinitrile(DCM2) and green emitting ultrathin layer of 10-(2-benzothiazolyl)-2,3,6,7-tetrahydro-1,1,7,7-tetramethyl-1H,5H, 11H(1)-benzopyropyrano(6,7-8-i,j)quinolizin-11-one(C545T) with different thicknesses of 0.05 nm, 0.10 nm and 0.20 nm. For comparing, a doped WOLED was also fabricated, in which C545 T and DCM2 are codoped into DPVBi layer to provide blue, green and red emission for obtaining white emission. The maximum luminance and power efficiency of the doped WOLED are 5 765 cd/m^2 at 16 V and 5.23 lm/W at 5 V, respectively, and its Commission Internationale de l'Eclairage(CIE) coordinate changes from(0.393 7, 0.445 3) at 5 V to(0.300 7, 0.373 8) at 12 V. When the thickness of the ultrathin C545 T layer in non-doped WLEDs increases, the emission luminance increases, but all non-doped devices are in the yellow white region. The device with 0.10-nm-thick C545 T has a maximum efficiency of 15.23 cd/A at 8 V and a maximum power efficiency of 6.51 lm/W at 7 V, and its maximum luminance is 10 620 cd/m^2 at 16 V. CIE coordinates of non-doped WLEDs with C545 T thickness of 0.05 nm, 0.10 nm and 0.20 nm are(0.447 3, 0.455 6),(0.464 0, 0.473 1) and(0.458 4, 0.470 0) at 8 V, respectively.展开更多
基金The authors would like to thank Prof. Feng Wang, Prof. Xuedong Bai, and Prof. Kaihui Liu for helpful discussions. This work was supported by the National Basic Research Program of China （No. 2012CB932301） and the National Natural Science Foundation of China （Nos. 90921012, 11321091, 51102144, 11274190, and 51102147）.
文摘Single-walled carbon nanotubes （SWCNTs） illuminated by white light should appear colored due to resonance Rayleigh scattering. However, true-color imaging of SWCNTs on substrates has not been reported, because of the extremely low scattering intensity of SWCNTs and the strong substrate scattering. Here we show that Rayleigh scattering can be greatly enhanced by the interface dipole enhancement effect. Consequently colorful SWCNTs on substrates can be directly imaged under an optical microscope by wide field supercontinuum laser illumination, which facilitates high throughput chirality assignment of individual SWCNTs. This approach, termed ＂Rayleigh imaging microscopy＂, is not restricted to SWCNTs, but widely applicable to a variety of nanomaterials, which enables the colorful nanoworld to be explored under optical microscopes.
基金supported by the National Natural Science Foundations of China (51961145101)Guangzhou Science & Technology Project (202007020005)+3 种基金the Project Supported by Guangdong Province Universities and Colleges Pearl River Scholar Funded Scheme (GDUPS, 2018) for Prof. Bingfu Leithe National Key R&D Program of China (2020YFB0407902)Guangdong Provincial Science & Technology Project (2021A0505050006 and 2021B0707010003)Guangdong Provincial Special Fund for Modern Agriculture Industry Technology Innovation Teams (2021KJ122)。
文摘The development of single-component white emitters for white light-emitting diodes(WLEDs)remains challenging.Herein,a rare earth-free white light-emitting composite is developed by assembling blue-emitting carbon dots(CDs)and yellow-emitting Cs_(2)InCl_(5)·H_(2)O:Sb^(3+)metal halide crystals via a facile liquid-liquid diffusion-assisted crystallization approach.The encapsulation mechanism is then analyzed.Depending on the ratios of blue/yellow emitters,these luminescent composites exhibit white light emission with tunable cold and warm hues.The composites also possess prominent ultraviolet resistance,thermal tolerance,and good stability at about 200°C.By employing such“CDs in metal halide”composites as a converter,a WLED is successfully fabricated with a high color rendering index of 93.6,benefiting from the assembled blue and yellow broadband emission.With this strategy,the developed composites show great promise in next-generation WLED lighting.
基金supported by the National Natural Science Foundation of China(No.50902042)the Natural Science Foundation of Hebei Province in China(Nos.A2014201035 and E2014201037)the Education Office Research Foundation of Hebei Province in China(Nos.ZD2014036 and QN2014085)
文摘SrZn2(PO4)2:Sm3+ phosphor was synthesized by a high temperature solid-state reaction in atmosphere. SrZn2(PO4)2:Sm3+ phosphor is efficiently excited by ultraviolet(UV) and blue light, and the emission peaks are assigned to the transitions of 4G5/2-6H5/2(563 nm), 4G5/2-6H7/2(597 nm and 605 nm) and 4G5/2-6H9/2(644 nm and 653 nm). The emission intensities of SrZn2(PO4)2:Sm3+ are influenced by Sm3+ concentration, and the concentration quenching effect of SrZn2(PO4)2:Sm3+ is also observed. When doping A+(A=Li, Na and K) ions, the emission intensity of SrZn2(PO4)2:Sm3+ can be obviously enhanced. The Commission Internationale de l'Eclairage(CIE) color coordinates of SrZn2(PO4)2:Sm3+ locate in the orange-red region. The results indicate that the phosphor has a potential application in white light emitting diodes(LEDs).
基金supported by the Major Project of Science and Technology Office of Fujian Province of China(No.2014H0042)the Natural Science Foundation of Fujian Province of China(No.2015J01664)+1 种基金the Project of Science and Technology Research of Quanzhou in Fujian Province of China(Nos.2013Z125 and 2014Z137)the 2016 Annual National or Ministries of the Quanzhou Normal University Prepare Research Foundation Project(No.2016YYKJ21)
文摘A kind of efficient non-doped white organic light-emitting diodes(WOLEDs) were realized by using a bright blue-emitting layer of 4,4-bis(2,2-diphenylvinyl)-1,1-biphenyl(DPVBi) combining with red emitting ultrathin layer of [2-methyl-6-[2-(2,3,6,7-tetrahydro-1H,5H-benzo[ij]quinolizin-9-yl)ethenyl]-4H-pyran-4-ylidene]propane-dinitrile(DCM2) and green emitting ultrathin layer of 10-(2-benzothiazolyl)-2,3,6,7-tetrahydro-1,1,7,7-tetramethyl-1H,5H, 11H(1)-benzopyropyrano(6,7-8-i,j)quinolizin-11-one(C545T) with different thicknesses of 0.05 nm, 0.10 nm and 0.20 nm. For comparing, a doped WOLED was also fabricated, in which C545 T and DCM2 are codoped into DPVBi layer to provide blue, green and red emission for obtaining white emission. The maximum luminance and power efficiency of the doped WOLED are 5 765 cd/m^2 at 16 V and 5.23 lm/W at 5 V, respectively, and its Commission Internationale de l'Eclairage(CIE) coordinate changes from(0.393 7, 0.445 3) at 5 V to(0.300 7, 0.373 8) at 12 V. When the thickness of the ultrathin C545 T layer in non-doped WLEDs increases, the emission luminance increases, but all non-doped devices are in the yellow white region. The device with 0.10-nm-thick C545 T has a maximum efficiency of 15.23 cd/A at 8 V and a maximum power efficiency of 6.51 lm/W at 7 V, and its maximum luminance is 10 620 cd/m^2 at 16 V. CIE coordinates of non-doped WLEDs with C545 T thickness of 0.05 nm, 0.10 nm and 0.20 nm are(0.447 3, 0.455 6),(0.464 0, 0.473 1) and(0.458 4, 0.470 0) at 8 V, respectively.
