Preparation And Optoeletronic Characteristics Of Two-dimention Photonic Crystal Nano-TiO₂

The monodisperse silica(Si O2) with different particle sizes were prepared firstly through the sol-sel method. Depending on the orthogonal design method, an optimal experimental plan of synthetizingthe monodisperse SiO2 microspheres could be obtained. The reaction temperature was 25°, the ammonium hydroxide(NH3·H2O) volume was 5/m L, the tetraethylortho silicate volume was 10/m L, and the reaction time was 10 h. At the same time, the analysis of the Fourier transform infrared spectroscopy(FT-IR) and the differential thermal gravity(TG and DSC) showed these samples was monodisperse silicon dioxide microspheres with mean grain size of 170~720nm, and the calcination of Si O2 gel crystal template in 550℃ could form the microspheres combined nect with each other in order to removing the template.The best experiment scheme of synthetizing TiO2 precursor sol could be achieved through the orthogonal design. The ratio of the material consumptions was 4 9 2 6 3 2(): : : 9:35:1.5:1Ti oc H C H O CH COOH H OV V V V ?. The macroporous TiO2 thin films were prepared by the dip-lift way based on the glue crystal template of the monodisperse Si O2 microspheres. Meanwhile, NaOH solution could be used to remove SiO2 gel crystal template. The optimum plan of preparing the macroporous TiO2 could be conluded by changing the experiment conditions. The composite film’s heat treatment temperature is 600℃,and the Na OH solution’s mass fraction is 10%.The crystalline phases and crystal grain size of the samples were analyzed by X-ray diffractometer(XRD). The results showed, with the increase of heating treatment temperature, the anatase phase gradually shifted to the rutile phases, and the grain sizes of the thin film samples decreased comparing to the powder sample. The scanning electron microscope(SEM) was be used to characterize the microstructure of the samples. The lattice vibration modes of samples were characterized by laser Raman spectroscopy(Raman). The photogenerated electron transition behavior could be analyzed by the surface photovoltaic spectroscopy(SPS), the ultraviolet-visible absorption spectra(UV-VIS), the external field induced surface photovoltaice spectrum(EFISPS) and on the transient photovoltaic spectrum. The results showed that better surface photovoltaic response and the wider range of the photovoltaic response could be obtained by increasing the heating treatment temperature.