Organic solar cells (OSCs) have been widely studied due to the advantages of easy fabrication, low cost, light weight, good flexibility and sufficient transparency. In this work, flexible and semitransparent OSCs were successfully fabricated with the adoption of both polyimide/silver nanowires (PI/AgNW) and a conducting polymer PEDOT:PSS named PH1000 as the transparent conductive electrodes (TCEs). It is demonstrated that PI/AgNW is more suitable as a cathode rather than an anode in the viewpoint of its work function, photovoltaic performance, and simulations of optical properties.
View Article and Find Full Text PDFAlthough tremendous progress has recently been made in quasi-2D perovskite light-emitting diodes (PeLEDs), the performance of red PeLEDs emitting at ≈650-660 nm, which have wide prospects for application in photodynamic therapy, is still limited by an inefficient energy transfer process between the quasi-2D perovskite layers. Herein, a symmetric molecule of 3,3'-(9H-fluorene-9,9-diyl)dipropanamide (FDPA) is designed and developed with two functional acylamino groups and incorporated into the quasi-2D perovskites as the additive for achieving high-performance red PeLEDs. It is demonstrated that the agent can simultaneously diminish the van der Waals gaps between individual perovskite layers and passivate uncoordinated Pb related defects at the surface and grain boundaries of the quasi-2D perovskites, which truly results in an efficient energy transfer in the quasi-2D perovskite films.
View Article and Find Full Text PDFA novel aromatic diamine containing pyridyl side group, 4-pyridine-4,4-bis(3,5-dimethyl-5-aminophenyl)methane (PyDPM), was successfully synthesized via electrophilic substitution reaction. The polyimides (PIs) containing pyridine were obtained via the microwave-assisted one-step polycondensation of the PyDPM with pyromellitic dianhydride (PMDA), 3,3',4,4'-biphenyltetracarboxylic dianhydride (BPDA), 3,3',4,4'-diphenylether tetracarboxylic dianhydride (ODPA) and 4,4'-(hexafluoroisopropylidene)diphthalic anhydride (6FDA). Contrarily to the reported similar PIs, these PIs exhibit much higher thermal stability or heat resistance, i.
View Article and Find Full Text PDFWe present an investigation of deep-blue fluorescent polymer light-emitting diodes (PLEDs) with a novel functional 1,3,5-triazine core material (HQTZ) sandwiched between poly(3,4-ethylene dioxythiophene):poly(styrene sulfonic acid) layer and poly(vinylcarbazole) layer as a hole injection layer (HIL) without interface intermixing. Ultraviolet photoemission spectroscopy and Kelvin probe measurements were carried out to determine the change of anode work function influenced by the HQTZ modifier. The thin HQTZ layer can efficiently maximize the charge injection from anode to blue emitter and simultaneously enhance the hole mobility of HILs.
View Article and Find Full Text PDFInverted-type polymer light-emitting diodes with Au nanoparticles modified ITO cathode has exhibited improved brightness from 5900 to 15,000 cd m(-2) (1.5-fold enhancement) and enhanced luminous efficiency from 4.4 to 10.
View Article and Find Full Text PDFA new series of monoammonium-based organic electrolytes with the tetrafluoroborate (BF(4)(-)) counteranion have been synthesized. Replacing the pendant ethyl groups in the fluorenyl unit with 4-ethoxyphenyl groups dramatically improves both solubility and morphological stability. The characterization of the alcohol-processable amorphous ionic compounds as an electron-injection layer in organic light-emitting diodes (OLEDs) reveals that the organic electrolyte that comprises a rigid linear-conjugated unit provides better device performance, with respect to its counterpart containing a branched bulky moiety.
View Article and Find Full Text PDFChem Commun (Camb)
December 2008
Two classes of bulk high-Z polymer composites were prepared, which exhibit scintillation properties for gamma-radiation detection.
View Article and Find Full Text PDFThe role of dissolved oxygen, and of active species generated by photo-induced reactions with oxygen, in the photocatalytic degradation of phenol was investigated using polymer [poly-(fluorene-co-thiophene) with thiophene content of 30%, so-called PFT30] sensitized TiO2 (PFT30/TiO2) under visible light irradiation. The photoluminescent (PL) quantum yield of PFT30/TiO2 was about 30% of that of PFT30/Al(2)O(3), proving that electron transfer took place between the polymer and TiO2. The result that photocatalytic degradation of phenol was almost stopped when the solution was saturated with N(2) proved the importance of O(2).
View Article and Find Full Text PDFPhotocatalytic removal of phenol, rhodamine B, and methyl orange was studied using the photocatalyst ZnO/poly-(fluorene-co-thiophene) (PFT) under visible light. After 2 h irradiation with three 1 W LED (light-emitting diode) lights, about 40% removal of both phenol and methyl orange was achieved; rhodamine B was completely degraded to rhodamine. Diffuse reflectance spectra showed that the absorbance range of PFT/ZnO was expanded from 387 nm (ZnO) to about 500 nm.
View Article and Find Full Text PDFSoluble poly(3,6-fluorene) and its copolymer were synthesized by nickel-catalyzed coupling. Poly(3,6-fluorene) exhibited the optical band gap of 3.6 eV, the emission maximum at 347 nm, and the HOMO level of -6.
View Article and Find Full Text PDFChem Commun (Camb)
October 2005
An ultraviolet-emitting conjugated polymer, poly(9,9'-alkyl-3,6-silafluorene) with a wide band gap of 4.0 eV, has been synthesized and characterized.
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