Mesoporous TiO2microsphere(MTM)was synthesized via a simple solution route and then mixed with commercial TiO2(P25)to form highly homogeneous and stable TiO2colloid by simple hydrothermal treatment.The TiO2colloid was coated onto the plastic conductive substrate to prepare mesoporous TiO2film for flexible dye-sensitized solar cells(DSSCs)by low-temperature heat treatment.The influence of MTM content on the physicochemical properties of the flexible TiO2film was characterized by scanning electron microscope,transmission electron microscopy,X-ray diffraction,energy-dispersive X-ray spectrometer,N2adsorption-desorption isotherms,UV–vis absorption and diffuse reflectance spectra.It is revealed that with increasing the MTM content,the dye-loading capability of TiO2film and light-harvesting efficiency of flexible DSSCs are improved due to MTM having high surface area and acting as a light scattering center,respectively,resulting in the enhancement of photocurrent of flexible DSSCs.However,more and larger cracks having negative effect on the performances of flexible DSSCs are formed simultaneously.Under the optimal condition with MTM content of 20%,a flexible DSSC with overall light-to-electric energy conversion efficiency of 2.74%is achieved under a simulated solar light irradiation of 100 mW cm 2(AM 1.5),with 26%improvement in comparison with DSSCs based on P25 alone.
FAN LeQingCHEN YuanWU JiHuaiLI ZhaoLeiXIAO YaoMingHUANG MiaoLiangYU HaiJun
The flower-like microsphere Bi2WO6 with an average diameter of 2.5 μm is synthesized by a simple hydrothermal method in the presence of surfactant sodium dodecyl sulfate （SDS） or polyvinylpyrrolidone （PVP）. The crystalline phase, compositions, morphology, microstructure, surface area and band gap energy of the Bi2WO6 are characterized by X-ray diffraction, X-ray energy-dispersive spectrum, scanning electron microscopy, transmission electron microscopy and absorption spectra. It is found that surfactant has a significant influence on the microstructure and properties of the samples. The surfaetant SDS en- hances the surface area and photocatalytic activity of Bi2WO6, while the surfactant PVP has an opposite effect. Under Xe lamp irradiation, the Bi2WO6 sample prepared in the presence of SDS can degrade dye Rhodamine B （RhB） effectively.
HUANG Yi,WU JiHuai,HUANG MiaoLiang,LIN JianMing & HUANG YunFang Engineering Research Center of Environment-Friendly Functional Materials,Ministry of Education
A counter electrode for dye-sensitized solar cell (DSSC) was prepared by coating poly(3,4-ethylenedioxythiophene): poly(styrenesulfonate) (PEDOT:PSS) with high transparency and adhesion on a conducting FTO glass at low temperature. The surface morphology, conductivity, sheet resistance, redox properties and photoelectric properties of the PEDOT:PSS/carbon electrodes were observed using scanning electron microscopy, a four-probe tester and a CHI660D electrochemical measurement system. The experimental results showed that DSSCs had the best photoelectric properties for PEDOT:PSS/carbon counter electrodes annealed at 80°C under vacuum conditions. The overall energy conversion efficiency of the DSSC with PEDOT:PSS/carbon counter electrode and barrier layer reached 7.61% under irradiation from a simulated solar light with intensity of 100 mW/cm2 (AM 1.5). The excellent photoelectric properties, simple preparation procedure and low cost allow the PEDOT:PSS/carbon electrode to be a credible alternative electrode for use in DSSCs.
