【作者】 简泽浪；

【导师】 陈文；

【作者基本信息】 武汉理工大学 ， 材料物理与化学， 2010， 硕士

【摘要】 自从1969年Deb发现WO3薄膜的电致变色效应之后,电致变色材料得到了广泛应用。钒氧化物在不同价态表现出不同颜色,并且V2O5具有层状结构,有利于电子和离子的传输。V2O5是一种很好的电致变色主体材料,Mo掺杂可以大大提高其性能,因而Mo掺杂V2O5电致变色材料被广泛研究。为了找到一种更有效的制备Mo掺杂V2O5薄膜工艺,本文尝试了溶胶凝胶结合电泳沉积的工艺。研究了沉积工艺最主要的影响因素电压对成膜质量的影响,寻找最佳的沉积Mo掺杂V2O5薄膜的电压。同时研究了Mo掺杂V2O5薄膜的动力学性能。得出以下结论：1.Mo掺杂V2O5薄膜的最佳沉积电压为1.0 V,最佳沉积时间为2 min。其厚度为340 nm,电荷密度为35.8 mC/cm2,50次循环后容量保持率仍然高达90%左右,消色和着色响应时间分别为4 s和5 s,透过变化率达到最大值,为62.5%,相比与纯的V2O5薄膜和浸渍提拉工艺制备的Mo掺杂V2O5薄膜都大大提高。采用合理的沉积电压可以制备出高性能的电致变色薄膜,大大提高其容量和透过变化率,电泳沉积工艺是一种非常有效的制备工艺。2.以最佳沉积电压1.0 V,以不同沉积时间制备了一系列薄膜,研究了沉积时间对薄膜厚度以及电化学性质的影响。结果表明,随着沉积时间增加,薄膜厚度增加,其单位面积沉积的Mo掺杂V2O5溶胶的量随之增加,所以容量随着沉积时间增加,薄膜的着色/消色时间也相应的增加。这可能是由于Li+在Mo掺杂V2O5薄膜中传输,薄膜越厚,其传输距离越大,使得响应时间增加。沉积时间为30 s时,由于沉积时间过短,薄膜表面吸附没有达到平衡,薄膜表面形成不均一的薄膜,影响其循环稳定性,使其容量衰减较沉积电压为2 min和5 min制备的薄膜严重。3.薄膜厚度与透过率成反比关系,但是薄膜在消色态和着色态的透过率变化快慢却不相同,导致其透过变化率在某一厚度下达到最大值。本实验中,沉积电压为2 min制备的薄膜透过率最大。致密的薄膜循环性能好,但是其消色和着色响应时间变慢。通过对极化前后的AFM形貌观察,致密薄膜极化前后形貌没有太大的变化,只是在局部地方形成鼓包,薄膜在循环过程中结构保持较好,这可能是导致致密薄膜表现出较好的循环性能的原因。但是薄膜致密会使Li+传输变缓,导致其扩散困难,响应时间增加。更多还原

【Abstract】 In 1969, Deb found WO3 thin films have electrochromic properties. After that, the Electrochromic materials have been extensively developed. Vanadium oxides have different color when V at different valence states. V2O5 has layered structure which is conducive to the transmission of electrons and ions. And Mo doped V2O5 have been extensively studied as electrochromic material.In this paper, in order to find a more effective technology to preparation of Mo doped V2O5 thin films, a method combining sol-gel and electrophoresis deposition was tried. The effect of deposition voltages to performance were studied to find best deposited voltage. The results show that best deposition voltage is 1.0 V. In this deposition voltage, the effect of time to the performance of Mo doped V2O5 thin films. And the Mo doped V2O5 thin films were also prepared by dip-coating, which were compared with films prepared by electrophoresis deposition. Last, the dynamics performance of Mo doped V2O5 thin films prepared by electrophoresis deposition. This dissertation mainly consists of the following several conclusions:1. The best deposition voltage of Mo doped V2O5 thin films is 1.0V. The thickness is 340 nm and the charge density is 35.8 mC/cm2. After 50 cycles, the capacity retention rate remains as high as 90%.The bleached and colored response time was 4 s and 5 s, respectively. The maximal transmittance change for the film is 62.5%. Which were greatly enhanced compared with pure V2O5 film and Mo doped V2O5 films preparated by dip-coating. High-performance films can be prepared by electrophoresis deposition with appreciate conditions. Electrophoresis deposition is promising technology to prepare electrochromic films.2. A series of films were prepared with different of deposited time and deposition voltage of 1.0 V. We studied the effect of deposited time to the thickness and properties of Mo doped V2O5 thin films. The results showed that with the deposition time prolong, the thickness and charge density of film increases. But the bleached and colored response time also increase. The way of Li+ ions is longer when the thickness is thicker. The cycle stability of film deposited with 30 s is worse than films deposited with 2 min or 5min. We thought that the absorption between substrate and sol-gel did not reach equilibrium.3. The relationship between thickness and transmission of film is opposite. The transmission of films at bleached state and colored state shows different change rate, which lead to maximal transmittance change at the specific thickness. In this paper, the film prepared with 2 min shows maximal transmittance change, which is about 62.5%. Compact film shows better cycle performance, but response times of the consumer color also increase. Film remains its morphology in the main and only few of drums generated. Hence, film with compact surface exhibits good cycle stability. Film has compact surface, which lead Li+ diffuses slower and response times increase.4. The electrochromism of Mo doped V2O5 films can be considered as the Li+ ions are electron transfer model.更多还原