【作者】 王诗铭；

【导师】 王恩波；

【作者基本信息】 东北师范大学 ， 无机化学， 2013， 博士

【摘要】 开发新能源和节能是环境可持续发展的两个重要方面。近年来，染料敏化太阳能电池在利用太阳能方面显示出了一定的潜力；而电致变色智能窗可以通过改变外电压来改变它的透过率，以此来调节室内的光线和热量。在建筑节能领域中这种先进的调光玻璃显示了极大的经济效益。多金属氧酸盐（多酸）是一类具有纳米结构的金属氧簇，有着独特的结构和电化学性能，它在染料敏化太阳能电池和电致变色智能窗方面有极大地应用潜力。在这篇论文中，通过三种不同的方法制备了多酸-TiO₂复合膜，即：层接层法、溶胶-凝胶-丝网印刷法和电沉积法。根据复合膜不同的性能，将其成功的应用于高性能染料敏化太阳能电池和电致变色智能窗中。并对带有多酸-TiO₂复合膜的器件的性能做了全面的测试。1、利用LBL法制备的H3PW₁₂O₄₀(PW₁₂)-TiO₂薄膜作为染料敏化太阳能电池的新型界面层。以多酸基薄膜为界面层的电池的性能做了J–V曲线测试、暗电流测试、开路电压衰减测试和单色光转化效率测试。多酸基的界面层有加速电子流动，抑制暗电流的作用。相比于没有界面层的电池，光电转化效率有54%的提升；相比与进行TiCl4水溶液前处理的电池，效率有20%的提升。2、利用溶胶-凝胶法制备的PW₁₂/TiO₂复合物，并与P25混合，利用丝网印刷法制备的薄膜作为染料敏化太阳能电池的光阳极。在染料敏化太阳能电池中，多酸可以起到减小电子复合、延长电子寿命的作用。利用PW₁₂/TiO₂复合物作为阳极的电池性能比纯P25作为阳极的电池有明显提高。转化效率有22.8%的提升。利用电化学阻抗和开路电压衰减法测试了多酸在光阳极中起的作用。3、开发在多孔TiO₂基底上电沉积多酸阴离子的方法。并以其作为电致变色智能窗的电致变色电极。这种方法具有简单、快速、易操作、低成本等优点。利用此方法制备的[NaX₅W₃₀O₁₁₀]n–（X=P, n=14; S, n=9）基电致变色智能窗表现出以下优势：褪色态透光性好、光学反差高、良好的长期稳定性和高的着色效率。4、利用电沉积方法将不同结构的多酸沉积到多孔TiO₂基底上，探索多酸结构与电致变色性能的关系。Wells–Dawson结构的多酸K6[P2W18O62]14H2O （P2W18）和它的单缺位衍生物K₁₀[P₂W₁₇O₆₁]20H₂O （P₂W）₁₇)被成功的应用于电致变色智能窗。P2W17基电致变色智能窗在620nm处最大有93.1%的光学反差、着色时间0.90s、着色效率205.3cm2C–1。由于二者结构上的差异，P2W18基电致变色智能窗的性能稍差，其在646nm处的最大光学反差为48.7%、着色时间为0.97s、着色效率为176.8cm2C–1。并且二者均有良好的长期稳定性。更重要的是，我们首次研究了P2W17在不同电压下的近红外电致变色性质。在多酸基电致变色智能窗中，P2W17基智能窗有着最佳的性能。更多还原

【Abstract】 Exploring new energy and energy saving both play important roles in attaining thepurpose of sustainable development. Dye sensitized solar cells （DSSCs） are promisingphotovoltaic device in the utilizing of solar energy. Electrochromic （EC） smart windows maybe electronically darkened or lightened with small applied voltages, allowing for controllingof daylight, solar heat gain, and internal heat loss through windows of the buildings andvehicles. Polyoxometalates （POMs） represent a well–known class of metal oxide nanoclusterswith intriguing structures and electrochemical properties, which have extreme potential to beapplied in photovoltaic and electrochromic devices. In this paper, POMs–TiO₂compositefilms have been fabricated by layer–by–layer （LBL）, screen printing method andelectrodeposition method. The POMs–TiO₂composite films are successfully applied inDSSCs and EC smart windows. The performances of the devices have been fully tested.1. A new H3PW₁₂O40(PW₁₂)–based interfacial layer for DSSCs has been fabricated by LBLmethod. The cells have been systemically tested by photocurrent–voltage curve,dark–current measurement, open–circuit voltage decay and the monochromatic incidentphoton–to–photocurrent conversion efficiency techniques. The PW₁₂–based interfaciallayer accelerates electron transfer and retards recombination, eventually leading to theenergy conversion efficiency increase efficiently. The investigations indicate that theenergy conversion efficiency of (PW₁₂/TiO₂)3–DSSC is significantly enhanced by54%at100mW cm–2compared with the DSSC with no–treatment and20%compared withTiCl4–treatment DSSC. POM is firstly introduced to the interfacial layer in modifying thephotoanode to accelerate electron transfer and retard recombination for improving theefficiency of DSSC in this work.2. PW₁₂–TiO₂composite have been successfully introduced into the photoanode of thedye–sensitized solar cells to reduce the recombination of the electrons which results inlonger electron lifetime. The cells with PW₁₂modified photoanodes show betterperformance than the cell with pure P25photoanode. The overall improvement of theefficiency is22.8%by using the PW₁₂modified photoanode. The effect of the POM wasstudied by electrochemical impedance spectroscopy and open–circuit voltage decaymeasurement. The results show that the electron lifetime becomes longer following by theincreasing of the amount of the PW₁₂.3. A new electrodeposited method has been explored to prepare POMs-porous TiO₂composie films. The composite films have been applied in EC smart windows. It is a simple and low cost process to prepare the EC film by the solution–basedelectrodeposition method. The [NaX5W30O110]n–（X=P, n=14; S, n=9）–based EC smartwindows perform high transparency in bleach state, high optical contrast, long durability,and high coloration efficiency.4. Using the electrodeposite method the performance of the The Wells–Dawson type POMK6[P2W18O62]14H2O （P2W18） and its derivate K10[P2W17O61]20H2O （P2W17） has beenelectrodeposited on porous TiO₂substrate and applied in EC smart windows. Themaximum optical contrast for the P2W17–based EC smart window is93.1%at thewavelength of620nm and for the K6[P2W18O62]14H2O P2W18–based EC smart window is48.7%at646nm. The coloration time extracted for a90%transmittance for theP2W17–based EC smart window is0.9s and for the P2W18–based smart window is0.97s;the coloration efficiency for the P2W17–based EC smart window is205.3cm2C–1and theP2W18–based smart window is176.8cm2C–1. Both of the P2W17–and P2W18–based ECsmart windows have the features of remarkable durability over1000cycles. TheP2W17–based smart window has larger optical contrast and higher coloration efficiencythan the P2W18–based smart window. More significantly is the near–infrared behavior ofthe P2W17under different applied potentials was recorded for the first time by using thesmart window. We believe the performance of the P2W17–based smart window is thestate–of–the–art among the POMs–based EC smart windows.更多还原