A very-high color rendering index white organic light-emitting diode(WOLED) based on a simple structure was successfully fabricated. The optimized device exhibits a maximum total efficiency of 13.1 and 5.4 lm/W at 1,0...A very-high color rendering index white organic light-emitting diode(WOLED) based on a simple structure was successfully fabricated. The optimized device exhibits a maximum total efficiency of 13.1 and 5.4 lm/W at 1,000 cd/m2. A peak color rendering index of 90 and a relatively stable color during a wide range of luminance were obtained. In addition, it was demonstrated that the 4,40,400-tri(9-carbazoyl) triphenylamine host influenced strongly the performance of this WOLED.These results may be beneficial to the design of both material and device architecture for high-performance WOLED.展开更多
Herein we present emission color-tunable and multi-functional lanthanide(Ⅲ)luminescent hybrid materials(Ln(DPA)@AC-CDs)by mixing aminoclay(AC),2,6-pyridinedicarboxylic acid(DPA),Ln3+(Ln=Eu,Tb or Eu and Tb in differen...Herein we present emission color-tunable and multi-functional lanthanide(Ⅲ)luminescent hybrid materials(Ln(DPA)@AC-CDs)by mixing aminoclay(AC),2,6-pyridinedicarboxylic acid(DPA),Ln3+(Ln=Eu,Tb or Eu and Tb in different molar ratios),and carbon dots(N,S-CDs)in water,showing high quantum yields up to 58.8%.The emission colors can be finely tuned by altering the excitation wavelength and the amounts of the components,and white light emission(CIE-(0.27,0.25))can be achieved for sample Eu1Tb2(DPA)@AC-CDs under 325 nm light irradiation.In addition,under 365 nm UV light excitation,the Eu(DPA)@AC-CDs powder exhibits red luminescence due to the sensitization effect of N,S-CDs on Eu^3+,which turns to bright blue when the powder is dispersed in water attributed to the high dispersion of the aggregated N,S-CDs particles.These luminescent properties afford Ln(DPA)@AC-CDs potential candidates for designing optoelectronic devices like WLEDs or in information encryption applications.展开更多
In this study, small- and large-particle-diameter phosphor powders were mixed together（hybrid phosphors）to balance light efficacy and angular color uniformity and pursue optimal results. Phosphor with small-particle...In this study, small- and large-particle-diameter phosphor powders were mixed together（hybrid phosphors）to balance light efficacy and angular color uniformity and pursue optimal results. Phosphor with small-particlediameter of 4 lm was employed and it was mixed into each large-particle-diameter phosphor of 10, 16, 22, and 26 lm,at mass percentage from 0 % to 50 % with an interval of10 %, respectively. Remote phosphor package was adopted and overall phosphor concentration was kept constant for better comparison. Moreover, absorption coefficient labs,scattering coefficient lscaand extinction coefficient lext of each hybrid phosphors were calculated based on Mie theory to further discuss the experiment results. Results show that, the introduction of small-particle-diameter phosphor to large one can highly improve angular color uniformity while only slightly reduce light efficacy. The optimal performance with angular color uniformity of91.6 % as well as normalized light efficacy of 95.7 % is achieved in the white light emitting diode with hybrid phosphors consisting of 60 wt% powder of 22 μm and40 wt% powder of 4 μm.展开更多
In this Letter, we propose a modified hybrid linear and nonlinear post-equalizer to aid pre-convergence of space–time block coding（STBC） decoding in the formulated multiple-input-single-output（MISO） visible light...In this Letter, we propose a modified hybrid linear and nonlinear post-equalizer to aid pre-convergence of space–time block coding（STBC） decoding in the formulated multiple-input-single-output（MISO） visible light communication（VLC） model. Meanwhile, we present a channel estimation algorithm, as the existing method is suboptimal. Experiments demonstrate that a data rate of 1 Gbit/s is easily achieved in 1.3 m indoor free space transmission with the bit error rate（BER） limited to 3.8 × 10^-3. Correspondingly, the Q factor can be improved to 3.13 d B compared to the pure linear equalizer case.展开更多
The interlayer(IL) plays a vital role in hybrid white organic light-emitting diodes(WOLEDs); however,only a negligible amount of attention has been given to n-type ILs. Herein, the n-type IL, for the first time,has be...The interlayer(IL) plays a vital role in hybrid white organic light-emitting diodes(WOLEDs); however,only a negligible amount of attention has been given to n-type ILs. Herein, the n-type IL, for the first time,has been demonstrated to achieve a high efficiency, high color rendering index(CRI), and low voltage trade-off.The device exhibits a maximum total efficiency of 41.5 lm W^(-1), the highest among hybrid WOLEDs with n-type ILs. In addition, high CRIs(80–88) at practical luminances(C1000 cd m^(-2)) have been obtained, satisfying the demand for indoor lighting. Remarkably, a CRI of 88 is the highest among hybrid WOLEDs. Moreover, the device exhibits low voltages, with a turn-on voltage of only 2.5 V([1 cd m^(-2)), which is the lowest among hybrid WOLEDs. The intrinsic working mechanism of the device has also been explored; in particular, the role of n-type ILs in regulating the distribution of charges and excitons has been unveiled. The findings demonstrate that the introduction of n-type ILs is effective in developing high-performance hybrid WOLEDs.展开更多
The Hefei Advanced Light Facility(HALF)proposed by the National Synchrotron Radiation Laboratory is a green-field vacuum ultraviolet and soft X-ray diffraction-limited storage ring light source with a beam energy of 2...The Hefei Advanced Light Facility(HALF)proposed by the National Synchrotron Radiation Laboratory is a green-field vacuum ultraviolet and soft X-ray diffraction-limited storage ring light source with a beam energy of 2.2 GeV and emittance goal of less than 100 pm rad.Inspired by the ESRF-EBS hybrid multi-bend achromat(HMBA),SLS-2,and Diamond-II lattices,we have proposed and designed a modified H6BA lattice as the baseline lattice of the HALF storage ring with 20 identical cells and a natural emittance of approximately 86 pm rad.In this paper,three other types of HMBA lattices including two H7BA lattices and a H6BA lattice are designed for HALF with the same number of cells.The main storage ring proper-ties of these four HMBA lattices are compared.Because the intra-beam scattering(IBS)effect is significant in the HALF storage ring,we calculate and compare the equilibrium emittances of the four lattices with IBS included.These comparisons show that the present modified H6BA lattice,which has a relatively low equilibrium emittance and more straight sections,is preferred for the HALF storage ring after a comprehensive consideration.展开更多
Molecular materials exhibiting room temperature phosphorescence(RTP) have received much attention during last few years. It has been known that different stacking fashions(e.g., formation of polymorph) and aggregation...Molecular materials exhibiting room temperature phosphorescence(RTP) have received much attention during last few years. It has been known that different stacking fashions(e.g., formation of polymorph) and aggregation/crystal states could largely influence the RTP efficiency. However, whether the crystal morphology or shape could play a key role in modulation of the RTP has not been detected yet. In this work, we report that the dibenzothiophene(DBT) with the same molecular stacking fashion but different crystal morphologies can present alternated RTP performances. By modulation of the fluorescence and phosphorescence dual emission, a direct warm-white color light-emitting has also been successfully achieved. Moreover, the RTP emission can be further tuned through hybridization with β-cyclodextrin in different ratios, with the longest lifetime of 0.43 s.展开更多
A new organic-inorganic hybrid material,which shows photo-induced reduction of refractive index as well as volume contraction,is prepared using a sol-gel method.This material is coated on a Si substrate by spin-coatin...A new organic-inorganic hybrid material,which shows photo-induced reduction of refractive index as well as volume contraction,is prepared using a sol-gel method.This material is coated on a Si substrate by spin-coating to manufacture film.After irradiated by ultraviolet（UV） light with a deuterium lamp for 5 h, the thickness of film decreases largely by 55%,and the refractive index of film changes from 1.484 to 1.445 at 550 nm.The film＇s optical thickness exhibits an exponential change with the increasing irradiation time.Futhermore.the photo-patternning of the organic-inorganic hybrid film without any further process （wet etching and thermal curing） is performed utilizing the volume contraction on UV-light irradiation. This film has potential applications for fabrication of patterned filter array and apodizing filter by direct light writing,and also demonstrates good temperature stability and immunity to visible light exposure.展开更多
基金the National Natural Science Foundation of China (Grant Nos.61204087, 61306099)the Guangdong Natural Science Foundation (Grant No. S2012040007003)+2 种基金China Postdoctoral Science Foundation (2013M531841)the Fundamental Research Funds for the Central Universities (2014ZM0003, 2014ZM0034, 2014ZM0037, 2014ZZ0028)the Specialized Research Fund for the Doctoral Program of Higher Education (Grant No. 20120172120008)
文摘A very-high color rendering index white organic light-emitting diode(WOLED) based on a simple structure was successfully fabricated. The optimized device exhibits a maximum total efficiency of 13.1 and 5.4 lm/W at 1,000 cd/m2. A peak color rendering index of 90 and a relatively stable color during a wide range of luminance were obtained. In addition, it was demonstrated that the 4,40,400-tri(9-carbazoyl) triphenylamine host influenced strongly the performance of this WOLED.These results may be beneficial to the design of both material and device architecture for high-performance WOLED.
基金Project supported by the National Natural Science Foundation of China(21771050)Hebei Natural Science Foundation(B2017202048)+1 种基金Tianjin Natural Science Foundation(18JCYBJC17200)Educational Committee of Hebei Province(GCC2014035)
文摘Herein we present emission color-tunable and multi-functional lanthanide(Ⅲ)luminescent hybrid materials(Ln(DPA)@AC-CDs)by mixing aminoclay(AC),2,6-pyridinedicarboxylic acid(DPA),Ln3+(Ln=Eu,Tb or Eu and Tb in different molar ratios),and carbon dots(N,S-CDs)in water,showing high quantum yields up to 58.8%.The emission colors can be finely tuned by altering the excitation wavelength and the amounts of the components,and white light emission(CIE-(0.27,0.25))can be achieved for sample Eu1Tb2(DPA)@AC-CDs under 325 nm light irradiation.In addition,under 365 nm UV light excitation,the Eu(DPA)@AC-CDs powder exhibits red luminescence due to the sensitization effect of N,S-CDs on Eu^3+,which turns to bright blue when the powder is dispersed in water attributed to the high dispersion of the aggregated N,S-CDs particles.These luminescent properties afford Ln(DPA)@AC-CDs potential candidates for designing optoelectronic devices like WLEDs or in information encryption applications.
基金financially supported by the National Natural Science Foundation of China (No. 51272027)
文摘In this study, small- and large-particle-diameter phosphor powders were mixed together（hybrid phosphors）to balance light efficacy and angular color uniformity and pursue optimal results. Phosphor with small-particlediameter of 4 lm was employed and it was mixed into each large-particle-diameter phosphor of 10, 16, 22, and 26 lm,at mass percentage from 0 % to 50 % with an interval of10 %, respectively. Remote phosphor package was adopted and overall phosphor concentration was kept constant for better comparison. Moreover, absorption coefficient labs,scattering coefficient lscaand extinction coefficient lext of each hybrid phosphors were calculated based on Mie theory to further discuss the experiment results. Results show that, the introduction of small-particle-diameter phosphor to large one can highly improve angular color uniformity while only slightly reduce light efficacy. The optimal performance with angular color uniformity of91.6 % as well as normalized light efficacy of 95.7 % is achieved in the white light emitting diode with hybrid phosphors consisting of 60 wt% powder of 22 μm and40 wt% powder of 4 μm.
基金supported by the National Natural Science Foundation of China(No.61571133)the National Key Research and Development Program of China(No.2017YFB0403603)
文摘In this Letter, we propose a modified hybrid linear and nonlinear post-equalizer to aid pre-convergence of space–time block coding（STBC） decoding in the formulated multiple-input-single-output（MISO） visible light communication（VLC） model. Meanwhile, we present a channel estimation algorithm, as the existing method is suboptimal. Experiments demonstrate that a data rate of 1 Gbit/s is easily achieved in 1.3 m indoor free space transmission with the bit error rate（BER） limited to 3.8 × 10^-3. Correspondingly, the Q factor can be improved to 3.13 d B compared to the pure linear equalizer case.
基金the National Key Research and Development Program of China (Grant No. 2016YFF02033604)the Guangdong Natural Science Foundation (Grant Nos. 2014A030310253, 2016A030310360)+2 种基金the Fundamental Research Funds for the Central Universities (Grant No. 2015ZM070)the National Natural Science Foundation of China (Grant No. 51602065)the Guangdong Science and Technology Plan (Grant Nos. 2016A040403037, 2016A010101026)
文摘The interlayer(IL) plays a vital role in hybrid white organic light-emitting diodes(WOLEDs); however,only a negligible amount of attention has been given to n-type ILs. Herein, the n-type IL, for the first time,has been demonstrated to achieve a high efficiency, high color rendering index(CRI), and low voltage trade-off.The device exhibits a maximum total efficiency of 41.5 lm W^(-1), the highest among hybrid WOLEDs with n-type ILs. In addition, high CRIs(80–88) at practical luminances(C1000 cd m^(-2)) have been obtained, satisfying the demand for indoor lighting. Remarkably, a CRI of 88 is the highest among hybrid WOLEDs. Moreover, the device exhibits low voltages, with a turn-on voltage of only 2.5 V([1 cd m^(-2)), which is the lowest among hybrid WOLEDs. The intrinsic working mechanism of the device has also been explored; in particular, the role of n-type ILs in regulating the distribution of charges and excitons has been unveiled. The findings demonstrate that the introduction of n-type ILs is effective in developing high-performance hybrid WOLEDs.
基金the Fundamental Research Funds for the Central Universities(No.WK2310000107)the National Key Research and Development Program of China(No.2016YFA0402000)National Natural Science Foundation of China(Nos.12205299,11875259,12105284).
文摘The Hefei Advanced Light Facility(HALF)proposed by the National Synchrotron Radiation Laboratory is a green-field vacuum ultraviolet and soft X-ray diffraction-limited storage ring light source with a beam energy of 2.2 GeV and emittance goal of less than 100 pm rad.Inspired by the ESRF-EBS hybrid multi-bend achromat(HMBA),SLS-2,and Diamond-II lattices,we have proposed and designed a modified H6BA lattice as the baseline lattice of the HALF storage ring with 20 identical cells and a natural emittance of approximately 86 pm rad.In this paper,three other types of HMBA lattices including two H7BA lattices and a H6BA lattice are designed for HALF with the same number of cells.The main storage ring proper-ties of these four HMBA lattices are compared.Because the intra-beam scattering(IBS)effect is significant in the HALF storage ring,we calculate and compare the equilibrium emittances of the four lattices with IBS included.These comparisons show that the present modified H6BA lattice,which has a relatively low equilibrium emittance and more straight sections,is preferred for the HALF storage ring after a comprehensive consideration.
基金supported by the National Basic Research Program(2014CB932103)the National Natural Science Foundation of China(21301016,21473013)+1 种基金the Beijing Municipal Natural Science Foundation(2152016)the Fundamental Research Funds for the Central Universities
文摘Molecular materials exhibiting room temperature phosphorescence(RTP) have received much attention during last few years. It has been known that different stacking fashions(e.g., formation of polymorph) and aggregation/crystal states could largely influence the RTP efficiency. However, whether the crystal morphology or shape could play a key role in modulation of the RTP has not been detected yet. In this work, we report that the dibenzothiophene(DBT) with the same molecular stacking fashion but different crystal morphologies can present alternated RTP performances. By modulation of the fluorescence and phosphorescence dual emission, a direct warm-white color light-emitting has also been successfully achieved. Moreover, the RTP emission can be further tuned through hybridization with β-cyclodextrin in different ratios, with the longest lifetime of 0.43 s.
基金supported by the National Natural Science Foundation of China(Nos.60708013 and 60778025)the China Post-Doctoral Funding(No.20081463)the Zhejiang Provincial Natural Science Foundation(No. Y5080094)
文摘A new organic-inorganic hybrid material,which shows photo-induced reduction of refractive index as well as volume contraction,is prepared using a sol-gel method.This material is coated on a Si substrate by spin-coating to manufacture film.After irradiated by ultraviolet（UV） light with a deuterium lamp for 5 h, the thickness of film decreases largely by 55%,and the refractive index of film changes from 1.484 to 1.445 at 550 nm.The film＇s optical thickness exhibits an exponential change with the increasing irradiation time.Futhermore.the photo-patternning of the organic-inorganic hybrid film without any further process （wet etching and thermal curing） is performed utilizing the volume contraction on UV-light irradiation. This film has potential applications for fabrication of patterned filter array and apodizing filter by direct light writing,and also demonstrates good temperature stability and immunity to visible light exposure.
