The electrospinning technique provides a simple, cost-effective approach for producing polymeric and inorganic nanofibers with structures that vary with the processing parameters. In this paper, the polymer/TiO 2 hybrid nanofibers microporous membranes were prepared from a polymer solution containing titanium (IV) butoxide (TBT) by electrospinning technique. The as-spun nanofibers microporous membranes were placed in air for 5 h to allow complete hydrolysis. The morphology of the microporous membranes was observed using electron scanning microscopy (SEM) under vacuum condition. The uptake and porosity of microporous membranes were investigated by weighting method before and after soaking electrolyte. The ionic conductivity of the microporous membranes was measured using the complex impedance technique. The blocking cell of stainless steel/microporous membranes/stainless steel was used at 1-10 5 Hz frequency range at 25 ℃. The AC amplitude was 5 mV. The TiO 2 electrode was obtained by spreading titania paste (P25) on the conducting glass substrate using a doctor blade technique. The dye-sensitized solar cells (DSSCs) devices were fabricated based on the microporous membrane electrolyte by sandwiching a slice of the polymer/TiO 2 hybrid nanofibers microporous membrane between a dye-sensitized TiO 2 electrode and a Pt counter electrode. The edges of the cell were sealed with narrow strips of Surlyn hot melt. The morphology and three-dimensional structure of polymer/TiO 2 hybrid nanofibers microporous membranes did not markedly change after absorbing liquid electrolyte, which indicated that the introduction of TiO 2 into polymer nanofibers could improve the mechanical properties of the nanofibers. These also made the polymer/TiO 2 hybrid nanofibers microporous membranes possess high uptake and porosity. The TiO 2 content in hybrid nanofibers was about 50 wt% according to the TG results. The wetting and diffusion properties of hybrid nanofibers microporous membranes to liquid electrolyte were improved due to the incorporation of TiO 2 . The ionic conductivities of PVP/TiO 2 , PAN/TiO 2 hybrid nanofibers microporous membranes quasi-solid electrolyte could reach 2.81 mS•cm -1 and 2.62 mS•cm -1 , respectively, which were close to those of liquid electrolytes. The overall conversion efficiencies of quasi-solid DSSCs with N719 dye based on PVP/TiO 2 , PAN/TiO 2 hybrid nanofibers microporous membranes quasi-solid electrolyte reached 7.79% and 7.97%, respectively, which exceeded over 90% of the liquid electrolyte. Meanwhile, the fabricated DSSCs showed good long-term stability.
Collective Thomson scattering is theoretically investigated with the inclusion of the relativistic correction of (v/c) 2 . The correction is rather small for the plasma parameters inferred from the spectra of the thermal electron plasma waves in the plasma. Since the full formula of the corrected result is rather complicated, a simplified one is derived for practical use, which is shown to be in good agreement with the un-simplified one.
Polymer solar cells (PSCs) have attracted much attention due to their unique features, such as low cost, light weight, solution processibility, fast roll-to-roll production, and applications in large area flexible panels. High performance photovoltaic materials are usually low bandgap polymers, which are constructed as donor-acceptor (D-A) alternating copolymers, in order to better absorb solar energy. In the current work, three D-A conjugated polymers incorporating 1,2,4-triazole derivative as electron-withdrawing units and thiophene or benzo[1,2-b:4,5-b']dithiophene as electron-donating units have been synthesized. Their chemical structures of the corresponding intermediates and the polymers were confirmed with 1 H NMR, GC-MS or MALDI-TOF. All the polymers are readily dissolved in chloroform, THF, and toluene at room temperature, and the heat resistance and thermal stability of the three polymers are good enough for the application of PSCs. In chloroform solution, polymer PT-TZ shows only a absorption peak at 384 nm corresponding to the intramolecular charge transfer (ICT) interaction between thiophene unit and 1,2,4-triazole derivative. Whereas, polymers PB-TZ and PB-TTZT show three absorption peaks. The absorption peaks of PB-TZ and PB-TTZT in the UV region are attributed to the absorption of 1,2,4-triazole. Those in the visible region are ascribed to the π-π* transition derived from the polymer backbone and the ICT interaction respectively. Compared with PT-TZ and PB-TZ, the maximum absorption peak (λ max) of PB-TTZT is obviously red-shifted because of extending thiophene units in the conjugated main chain which increases effective conjugation of the main chain and broadens the absorption band. The highest occupied molecular orbital (HOMO) energy levels of three polymers are lower than-5.2 eV and the lowest unoccupied molecular orbital (LUMO) energy levels of them are higher than-3.8 eV, so these polymers are promising candidates for the effective applications of PSCs. The obvious two phase separation can be seen in the photoactive layer of PT-TZ and PC 61 BM (1∶2, w/w), so the monochromatic incident photon-to-electron conversion efficiency (IPCE) value of the PSC based on PT-TZ is very little. However, the photoactive layers of PB-TZ or PB-TTZT and PC 61 BM (1∶2, w/w) just show micro phase separation which is favourable to diffusion of exciton, so the IPCE values of the PSCs based on them are obviously higher than that of PT-TZ. The bulk-heterojunction photo
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