Solution‑Processed Transparent Conducting Electrodes for Flexible Organic Solar Cells with 16.61% Efficiency

Nonfullerene organic solar cells(OSCs)have achieved breakthrough with pushing the efficiency exceeding 17%.While this shed light on OSC commercialization,high-performance flexible OSCs should be pursued through solution manufacturing.Herein,we report a solution-processed flexible OSC based on a transparent conducting PEDOT:PSS anode doped with trifluoromethanesulfonic acid(CF3SO3H).Through a low-concentration and low-temperature CF3SO3H doping,the conducting polymer anodes exhibited a main sheet resistance of 35Ωsq−1(minimum value:32Ωsq−1),a raised work function(≈5.0 eV),a superior wettability,and a high electrical stability.The high work function minimized the energy level mismatch among the anodes,hole-transporting layers and electron-donors of the active layers,thereby leading to an enhanced carrier extraction.The solution-processed flexible OSCs yielded a record-high efficiency of 16.41%(maximum value:16.61%).Besides,the flexible OSCs afforded the 1000 cyclic bending tests at the radius of 1.5 mm and the long-time thermal treatments at 85°C,demonstrating a high flexibility and a good thermal stability.

Modified silicon carbide whisker reinforced polybenzimidazole used for high temperature proton exchange membrane

Polybenzimidazole containing ether bond（OPBI） was reinforced with silicon carbide whisker（m Si C） modified by 3-aminopropyltriethoxysilane（KH550）, and then doped with phosphoric acid（PA） to obtain OPBI/m Si C/PA membranes. These OPBI/m Si C/PA membranes have excellent mechanical strength and oxidative stability and can be used for high temperature proton exchange membrane（HT-PEM）. The tensile strength of OPBI/m Si C/PA membranes ranges from 27.3 to 36.8 MPa, and it increases at first and then decreases with the increase of m Si C content. The high m Si C content and PA doping level contribute to improving the proton conductivity of membranes. The proton conductivity of PBI/m Si C-10/PA membrane is 27.1 m S cm-1 at 170℃ without humidity, with an increase of 55.7% compared with that of OPBI/PA membrane. These excellent properties make OPBI/m Si C/PA membranes promising membrane materials for HT-PEM applications.

Influence of solvent on ion conductivity of polybenzimidazole proton exchange membranes for vanadium redox flow batteries

Polybenzimidazole(PBI)is a kind of proton transport membrane material,and its ion conductivity is a key factor affecting its application in vanadium redox flow batteries(VRFBs).The casting solvent of PBI has a significant influence on the acid doping level of PBI membranes which is closely related to ionic conductivity.In this paper,3,3′-diaminobenzidine(DABz)and 4,4′-Dicarboxydiphenylether(DCDPE)were used as raw materials by solution condensation to prepare the PBI with ether bond groups.The chemical structure of PBI was determined by1H NMR and FT-IR,and the prepared PBI had good solubility which can be dissolved in a variety of solvents.The PBI proton exchange membranes were prepared by solution coating with 5 different solvents of N,N-dimethylformamide(DMF),N,N-dimethylacetamide(DMAc),dimethyl sulfoxide(DMSO),1-methyl-2-pyrrolidone(NMP),methane sulfonic acid(MSA).The effects of different solvents on the ion conductivity and physicochemical properties were discussed in detail.The results showed that the PBI membrane prepared by using MSA as solvent(the PBI+MSA membrane)exhibits high water uptake,acid doping level and low vanadium ion permeability.The VRFB assembled with the PBI+MSA membrane exhibited higher coulombic efficiency(CE)99.87%and voltage efficiency(VE)84.50%than that of the commercial Nafion115 membrane at100 m A·cm-2,and after 480 cycles,the EE value can still be maintained at 83.73%.The self-discharge time of a single battery was recorded to be as long as 1000 h.All experimental data indicated that MSA is the best solvent for casting PBI membrane.

Hydrothermal fabrication of selectively doped organic assisted advanced ZnO nanomaterial for solar driven photocatalysis

Hydrothermal fabrication of selectively doped（Ag＋＋ Pd3＋） advanced ZnO nanomaterial has been carried out under mild pressure temperature conditions（autogeneous; 150°C）.Gluconic acid has been used as a surface modifier to effectively control the particle size and morphology of these ZnO nanoparticles. The experimental parameters were tuned to achieve optimum conditions for the synthesis of selectively doped ZnO nanomaterials with an experimental duration of 4 hr. These selectively doped ZnO nanoparticles were characterized using powder X-ray diffraction（XRD）, Fourier transform infrared spectroscopy（FT-IR）, UV–Vis spectroscopy and scanning electron microscopy（SEM）. The solar driven photocatalytic studies have been carried out for organic dyes, i.e., Procion MX-5B dye,Cibacron Brilliant Yellow dye, Indigo Carmine dye, separately and all three mixed, by using gluconic acid modified selectively doped advanced ZnO nanomaterial. The influence of catalyst, its concentration and initial dye concentration resulted in the photocatalytic efficiency of 89% under daylight.