Study On Preparation And Properties Of Ga:ZnO/V₂O₅ Nanocomposite Films For Smart Windows Application

Smart windows is a new type of building energy-saving glass. It can effectively control the light and temperature in door via changing the voltage. It is very valid to weaken the light pollution caused by the large area of curtain wall in modern building,because it can transform the color of the glass in the process of the whole dominating.However, the problem is that the materials used in the smart windows only can dominate the absorption and reflection in the visible or near-infrared light, so it can't simultaneously control the light and temperature in door. Considering the charged GZO nanocystals can block the near-infrared light via located surface plasmonic resonance,and the V₂O₅ can change the transmission of visible light under the electrochemical bias.So it is very important to make the metal oxide nanocomposite films?GZO/V₂O₅? out,which can control the transmission in both spectral bands.This work is to prepare GZO nanocrystal via high temperature nanaqueous solution.The GZO nanocrystal is characterized by FTIR. Then the GZO film is prepared by spin coating, and the influence of the subsequent processing on the quality of GZO films are analyzed comprehensively. The influence of the content of precursor on the Ga doping content, the annealing temperature and film thickness on the structure and morphology of GZO films is considered by XRD, AFM, SEM. At the same time, the photoelectric property is also considered by UV-vis and HALL. The result shows that the oleic acide ligand is on the surface of GZO nanocrystal. The organic compounds are removed by the UV treatments, and the carriers concentration is improved by thermal treatment in95%N₂ and 5%H₂. When the Ga doping content is up to 3.08% and the thickness is up to 1050 nm, the GZO films annealed in 500 ? have the best electric property. The average transmittance in visible region is 80%.In addition, The oxalato-vanadate clusters is prepared by mixing ammonium metavanadate with oxalic acid. the ligand is removed by surface chemical treatment.Then we combine the naked GZO nanocrystal with oxalato-vanadate clusters to get GZO/V₂O₅. The valence of V is dicussed by changing the ratio of ammonium metavanadate and oxalic acid. The influence of chemical surface treatment on the GZO nanocrystal is considered. The volume fraction of GZO nanocrystal in metal oxide nanocomposite is considered by XRD and Raman. The result shows that when the ratio of ammonium metavanadate with oxalic acid is 1:1, it proved to be?NH₄?₃VO₂?C₂O₄?2.2H₂ O. The ligands of oleic acide has been replaced by BF-, and the mobility and concentration of free carriers increases on account of removing the residue caused by thermal treatments. The V₂O₅ exist in a state of amorphous. And when thevolume fraction of GZO nanocrystal increases, the strength of raman peaks in the position of 140 cm-1, 992 cm-1 decrease, and the peaks in the 280 cm-1, 524 cm-1becomes wider. The transmittance of GZO/V₂O₅ is up to 75%. Finally the prospect of metal oxide nanocomposite applied in smart windows is analysed preliminary.