TiO2纳米片/巢状分级结构纳米阵列薄膜的制备及其在染料敏化太阳能电池中的应用

采用水热合成法在氟掺杂二氧化锡(FTO)导电玻璃基底上得到TiO2纳米阵列薄膜,并进一步通过NaOH溶液水热处理制备了由巢状纳米阵列及纳米片覆盖层构成的TiO2纳米阵列分级结构一体化薄膜.采用场发射扫描电镜(FE-SEM),X射线衍射(XRD),紫外-可见(UV-Vis)漫反射光谱和吸收光谱技术对TiO2薄膜的结构和性质进行表征.FE-SEM结果表明:分级结构TiO2薄膜膜厚为1.5μm,薄膜由一层纳米片覆盖层(约0.2μm高)和一层巢状纳米阵列层(约1.3μm高)组成.XRD谱图表明TiO2薄膜为锐钛矿相.UV-Vis光谱显示分级结构TiO2薄膜具有较强的光捕获能力和染料吸附能力.TiO2纳米片/巢状分级结构纳米阵列薄膜作为光阳极,可有效地提高染料敏化太阳能电池的光电转换效率,其短路电流(Jsc)为7.79mA·cm-2,开路电压(Voc)为0.80V,填充因子(FF)为0.40,光电转换效率(η)为2.48%,其光电转换效率较TiO2纳米阵列薄膜提高了近10倍.

Fabrication of Nanosheet/Nestlike Nanoarray Hierarchical TiO2 Film for Dye-Sensitized Solar Cell

A hierarchical configuration of TiO 2 nanoarray film,comprising a nestlike TiO 2 nanoarray layer integrated with a nanosheet network overlayer,was constructed.The hierarchical TiO 2 film was obtained by the post-hydrothermal treatment with NaOH solution on hydrothermally synthesized TiO 2-derived nanostructured arrays grown on fluorine-doped tin oxide substrate(FTO).The TiO 2 films were characterized by field-emission scanning electron microscope(FE-SEM),X-ray diffraction(XRD),ultraviolet-visible(UV-Vis) diffuse reflectance spectroscopy,and absorbance spectroscopy.FE-SEM shows that the hierarchical TiO 2 film with a thickness of 1.5 μm is composed of a nanosheet overlayer(～0.2 μm height) and the nestlike nanoarray layer(～1.3 μm height).XRD patterns display that the TiO 2 films have pure anatase phase structure.UV-Vis spectra reveal enhanced light scattering and dye adsorption ability of the hierarchical TiO 2 film.For the dye-sensitized solar cell(DSSC) based on the nanosheet/nestlike nanoarray hierarchical TiO 2 film,a short-circuit current(J sc) of 7.79 mA.cm-2,open-circuit voltage(V oc) of 0.80 V,fill factor(FF) of 0.40,and photoelectric conversion efficiency(η) of 2.48% are achieved.Within the dye-sensitized solar cell,the photoelectric conversion efficiency of the hierarchical TiO 2 film was nearly ten times higher than that of nanostructured array film.