Two soluble copolymers of fluorenone and dioctoxylbenzene （PFN） or anthracene （PFNAn） were synthesized through Heck polymerization, and were characterized by gel permeation chromatography （GPC）, FT-IR, IH-NMR, e...Two soluble copolymers of fluorenone and dioctoxylbenzene （PFN） or anthracene （PFNAn） were synthesized through Heck polymerization, and were characterized by gel permeation chromatography （GPC）, FT-IR, IH-NMR, elemental analysis and thermogravimetric analysis. The polymers possess good solubility in common organic solvents and high thermal stability with the Onset decomposition temperature at higher than 410 ℃. The photophysical properties of the polymers were investigated in both solutions and spin-coated films. Cyclic voltammetry results revealed that the copolymers possess higher electron affinity and reversible reduction/re-oxidation processes. Their electroluminescent properties were further investigated. PFN and PFNAn show stable and saturated red light emission with high thermal stability and high electron injection ability. This type of conjugated polymers may be promising for the applications as electron acceptors in polymer photovoltaic cells and electron transporting materials.展开更多
Lead halide perovskites have attracted extensive attention in recent years because of their excellent photoelectronic properties, such as high absorption coefficients,carrier mobilities, defect tolerances, and photolu...Lead halide perovskites have attracted extensive attention in recent years because of their excellent photoelectronic properties, such as high absorption coefficients,carrier mobilities, defect tolerances, and photoluminescence efficiencies. However, a key issue hindering their commercial application is the toxicity of lead. Replacing lead with other nontoxic elements is a promising solution to this problem.Considering their atomic radii, relative atomic masses, and electron arrangements, perovskites based on Sn, Bi, Sb, and other elements instead of Pb have been widely synthesized.Here, we summarized the growth methods, photoelectric properties, and device applications of these lead-free perovskites. First, we introduced several common growth methods for lead-free perovskites, including solution methods,solid-state reaction, and chemical vapor deposition methods.Second, we discussed the photoelectric properties and methods for optimizing these properties of lead-free perovskites with different structure dimensions. Finally, the applications of lead-free perovskites in solar cells, light-emitting diodes,and X-ray detectors were examined. This review also provides suggestions for future research on lead-free perovskites.展开更多
The charge-doping effect on the geometric and the electronic structures of organosilicon oligomers nSix(C=C)+y has been studied using density functional theory. Charge-doping can significantly lower the excitation ene...The charge-doping effect on the geometric and the electronic structures of organosilicon oligomers nSix(C=C)+y has been studied using density functional theory. Charge-doping can significantly lower the excitation energies. Interchain hole hopping mainly occurs between the π-conjugated units. A doped nSix(C=C)+y oligomer can undergo a structural rearrangement. The simulated UV/vis absorption peak of the rearranged structure is located at higher energy than the non-rearranged one. The hole transfer rate is significantly decreased if a doped molecule undergoes a rearrangement. These results offer a basis to explain previously observed experimental phenomena.展开更多
By controlling the reactant ratios, hydrothermal time, hydrothermal temperatures, p H values of the prepared solutions, and the concentrations of K3C6H5O7·2H2O, 1 mol% Eu3+ doped cubic phase of K5Gd9F32 and/or or...By controlling the reactant ratios, hydrothermal time, hydrothermal temperatures, p H values of the prepared solutions, and the concentrations of K3C6H5O7·2H2O, 1 mol% Eu3+ doped cubic phase of K5Gd9F32 and/or orthorhombic phase of Gd F3 micro/nanocrystals have been synthesized based on a hydrothermal method. For comparison, the sample was also synthesized by a co-precipitation method. The samples were characterized by X-ray diffraction(XRD) patterns, field emission scanning electron microscopy(FE-SEM) images, energy-dispersive spectroscopy(EDS) spectra, and photoluminescence(PL) excitation and emission spectra. By host Gd3+ sensitizing, the Eu3+ presents relatively strong emissions. The energy transfers from host Gd3+ to doping Eu3+ are observed in all the samples and the energy transfer plays an important role in the emission of Eu3+. Acting as a probe, the Eu3+ presents its distinct optical properties in the samples.展开更多
基金Projects(50803074, 50633050) supported by the National Natural Science Foundation of ChinaProject supported by the Opening Fund of State Key Laboratory of Powder MetallurgyStart-up Fund of Central South University, China
文摘Two soluble copolymers of fluorenone and dioctoxylbenzene （PFN） or anthracene （PFNAn） were synthesized through Heck polymerization, and were characterized by gel permeation chromatography （GPC）, FT-IR, IH-NMR, elemental analysis and thermogravimetric analysis. The polymers possess good solubility in common organic solvents and high thermal stability with the Onset decomposition temperature at higher than 410 ℃. The photophysical properties of the polymers were investigated in both solutions and spin-coated films. Cyclic voltammetry results revealed that the copolymers possess higher electron affinity and reversible reduction/re-oxidation processes. Their electroluminescent properties were further investigated. PFN and PFNAn show stable and saturated red light emission with high thermal stability and high electron injection ability. This type of conjugated polymers may be promising for the applications as electron acceptors in polymer photovoltaic cells and electron transporting materials.
基金Ministry of Science and Technology (2017YFA0205004, 2016YFA0200700)the Strategic Priority Research Program of the Chinese Academy of Sciences (XDB36000000)+2 种基金the National Natural Science Foundation of China (61704038, 21673054, 11874130, 12074086, 61307120, 61704038 and 11474187)the Open Research Fund Program of the State Key Laboratory of Low-Dimensional Quantum Physics (KF201902)the CAS Instrument Development Project (Y950291) for their support。
文摘Lead halide perovskites have attracted extensive attention in recent years because of their excellent photoelectronic properties, such as high absorption coefficients,carrier mobilities, defect tolerances, and photoluminescence efficiencies. However, a key issue hindering their commercial application is the toxicity of lead. Replacing lead with other nontoxic elements is a promising solution to this problem.Considering their atomic radii, relative atomic masses, and electron arrangements, perovskites based on Sn, Bi, Sb, and other elements instead of Pb have been widely synthesized.Here, we summarized the growth methods, photoelectric properties, and device applications of these lead-free perovskites. First, we introduced several common growth methods for lead-free perovskites, including solution methods,solid-state reaction, and chemical vapor deposition methods.Second, we discussed the photoelectric properties and methods for optimizing these properties of lead-free perovskites with different structure dimensions. Finally, the applications of lead-free perovskites in solar cells, light-emitting diodes,and X-ray detectors were examined. This review also provides suggestions for future research on lead-free perovskites.
基金supported by the National Natural Science Foundation of China (51073048)the Science Foundation for Leading Experts in Academy of Harbin City of China (2010RFJGG016)+1 种基金the Science Foundation of Heilongjiang Postdoctoral Grant of China (LBHQ07058)the Science Foundation for Elitists of Harbin University of Science and Technology
文摘The charge-doping effect on the geometric and the electronic structures of organosilicon oligomers nSix(C=C)+y has been studied using density functional theory. Charge-doping can significantly lower the excitation energies. Interchain hole hopping mainly occurs between the π-conjugated units. A doped nSix(C=C)+y oligomer can undergo a structural rearrangement. The simulated UV/vis absorption peak of the rearranged structure is located at higher energy than the non-rearranged one. The hole transfer rate is significantly decreased if a doped molecule undergoes a rearrangement. These results offer a basis to explain previously observed experimental phenomena.
基金supported by the National Natural Science Foundation of China(Grant Nos.61205217,11204258,and 11464021)Natural Science Foundation of Jiangxi Province of China(Grant No.20142BAB202003)+5 种基金Foundation of Jiangxi Educational Committee of China(Grant Nos.GJJ14564 and GJJ14565)High-level Talent Project of Xiamen University of Technology(Grant No.YKJ14031R)Foreign Cooperation Project of Xiamen University of Technology(Grant No.E2014223007)National Science Foundation for Distinguished Young Scholars of Fujian Province(Grant No.2012J06024)the Outstanding Young Scientific Research Personnel Training Plan in Colleges and Universities of Fujian Province(Grant No.JA13229)supported by the Basic Science Research Program through the National Research Foundation of Korea(NRF)funded by the Ministry of Science,ICT and Future Planning(Grant No.2013012655)
文摘By controlling the reactant ratios, hydrothermal time, hydrothermal temperatures, p H values of the prepared solutions, and the concentrations of K3C6H5O7·2H2O, 1 mol% Eu3+ doped cubic phase of K5Gd9F32 and/or orthorhombic phase of Gd F3 micro/nanocrystals have been synthesized based on a hydrothermal method. For comparison, the sample was also synthesized by a co-precipitation method. The samples were characterized by X-ray diffraction(XRD) patterns, field emission scanning electron microscopy(FE-SEM) images, energy-dispersive spectroscopy(EDS) spectra, and photoluminescence(PL) excitation and emission spectra. By host Gd3+ sensitizing, the Eu3+ presents relatively strong emissions. The energy transfers from host Gd3+ to doping Eu3+ are observed in all the samples and the energy transfer plays an important role in the emission of Eu3+. Acting as a probe, the Eu3+ presents its distinct optical properties in the samples.
