三氧化钨晶体拓扑结构生长行为及其电致变色性能

Growth behavior of WO_(3) crystal topological structure and its electrochromic properties

本研究利用种子层辅助的水热反应法,在导电玻璃上沉积生长三氧化钨(WO_(3))晶体结构薄膜.通过调控水热反应溶液中盐酸、草酸的浓度以及后处理温度,分别得到花朵状、海胆状和多孔花瓣状的WO_(3)晶体结构薄膜.采用扫描电子显微镜、X射线衍射、透射电子显微镜和电化学表征等手段研究了不同拓扑结构形成的机理及其对WO_(3)电致变色性能的影响.结果表明:盐酸中的Cl^(–)具有促进WO_(3)晶体沿c轴方向生长的作用,而草酸具有促进WO_(3)晶体沿a轴方向生长的作用;微米海胆状WO_(3)的着色效率为42.37 cm^(2)/C,远远大于WO_(3)花朵状(15.21 cm^(2)/C)和花瓣状(12.71 cm^(2)/C)的着色效率;经过淬冷处理的微米花WO_(3)表面呈多孔结构,其着色效率高达56.95 cm^(2)/C,是未淬冷处理、表面光滑微米花WO_(3)着色效率的近4倍,同时也优于微米海胆状WO_(3)的着色效率.

In this work,WO_(3) crystal structure films are deposited on conductive glass substrates by seed layer assisted hydrothermal reaction method.Through controlling the concentration of hydrochloric acid,oxalic acid,and the hydrothermal postprocessing temperature,the micro-peony,micro urchin-like,and porous petal-like WO_(3) crystal structures are obtained respectively.Scanning electron microscopy(SEM),X-ray diffraction(XRD),transmission electron microscopy(TEM) and electrochemical characterization are used to study the formation mechanism of different structures and their effects on the electrochromic properties of WO_(3) films.The Cl^(–) in HCl has a strong promoting role towards the c axis in WO_(3) crystal growth and oxalic acid has a promoting effect towards an a axis.In terms of color efficiency,the CE value of micro-urchin is 42.37 cm^(2)/C,far greater than those of two other WO_(3) structures,15.21 cm^(2)/C and 12.71 cm^(2)/C.Owing to the cold-water quenching treatment,the CE value of WO_(3) micro-peony with porous surface structure is 56.95 cm^(2)/C,quadruple CE value of the smooth surface structure,slightly better than that of the micro-urchin structure.