天然染料敏化太阳能电池的研究

【作者】 罗培辉；

【导师】 牛海军；

【作者基本信息】 黑龙江大学 ， 高分子化学与物理， 2010， 硕士

【摘要】 通过改性的溶胶-凝胶法和水热法合成了二种不同尺寸的二氧化钛粒子,将这两种二氧化钛粒子与商用的P25二氧化钛混合,制备了一种具有亚微米尺寸二氧化钛粒子,称为三元包裹型球状二氧化钛(Ternary-encapsulated spherical TiO2, TES-TiO2)。将制备的TES-TiO2通过阴极电泳沉积技术沉积在纳米晶介孔二氧化钛(Mesoporous TiO2, Meso-TiO2)涂敷的掺氟的氧化锡导电玻璃(Fluorine-doped SnO2 glass, FTO)上制备了用于染料敏化太阳能电池的双层二氧化钛电极。与双层Meso-TiO2/P25电极相比,基于Meso-TiO2/TES-TiO2电极的染料敏化太阳能电池的能量转换效率为6.49%,比Meso-TiO2/P25电极的5.94%提高了9.3%。制备的双层Meso-TiO2/TES-TiO2电极在高温煅烧时,同时引入高压电场(High-voltage electric field, HVEF)进行辅助晶化。结果,染料敏化太阳能电池的效率从6.49%变到7.05%进一步提高了8.6%。明显地,与通常应用于染料敏化太阳能电池活性层的20纳米左右的二氧化钛粒子相比,制备的具有亚微米尺寸、疏松多孔的TES-Ti02不仅增加了光散射效应,同时促进了分子染料的吸附和电解质的扩散。再者,HVEF的引入提供了更好的二氧化钛粒子之间的连接,使得电子在二氧化钛中更容易转输,避免了电荷的复合。本论文中第一次报道了使用美人蕉、串红和龙葵提取液作为染料敏化太阳能电池光敏剂的研究。通过使用美人蕉、串红、都柿和龙葵作为敏化剂组装成的染料敏化太阳能电池能量转换效率分别为0.29%,0.26%,0.13%和0.31%。我们用傅立叶转变红外光谱和紫外-可见吸收光谱分别研究了这四种天然染料的分子结构和光学吸收,用电化学阻抗光谱分析了电池内部界面的阻抗。结果表明在以都柿为光敏剂的染料敏化太阳能电池中,界面处存在较高的阻抗。更多还原

【Abstract】 A novel ternary-encapsulated spherical TiO2 (TES-TiO2) with submicron particle sizes was formed by blending commercial P25 TiO2 and two different sizes of TiO2 particles synthesized by modified sol-gel and hydrothermal methods. A double-layered TiO2 electrode for dye-sensitized solar cell (DSSC) was fabricated by depositing TES-TiO2 particles onto nanocrystalline mesoporous TiO2 (Meso-TiO2)-coated Fluorine-doped SnO2 glass (FTO) by a cathodic electrophoresis technique. Compared to double-layered Meso-TiO2/P25 electrodes, the energy conversion efficiency (η) of DSSC from the obtained Meso-TiO2/TES-TiO2 electrode was improved by 9.3%, from 5.94% to 6.49%. When the prepared double-layered Meso-TiO2/TES-TiO2 electrode was calcined at high temperature, a high-voltage electric field (HVEF) was introduced to assist crystallization. As a result,ηwas further enhanced by 8.6%, from 6.49% to 7.05%. Notably, compared to typical 20 run TiO2 nanocrystallites applied in the active layer of DSSC, the prepared loosely porous TES-TiO2 with submicron size increased the light scattering effect and promoted dye molecule adsorption and the diffusion of electrolytes.In addition, introduction of the HVEF provided better connection among TiO2 particles, which facilitated electron transport and avoided charge recombination.Study on DSSC with extracts of Canna indica L., Salvia splendens, Solanum nigrum L. as sensitizers is firstly reported in this paper. Solar cells were assembled by using natural dyes extracted from Canna indica L., Salvia splendens, cowberry and Solanum nigrum L. as sensitizers. The energy conversion efficiency of the cells sensitized with dyes of Canna indica L., Salvia splendens, cowberry and Solanum nigrum L. was 0.29%,0.26%,0.13% and 0.31%, respectively. We present FTIR and UV-vis spectroscopy studies of structures and light absorption of these four kinds of natural dyes. The electrochemical impedance spectroscopy (EIS) was used to analyze the interface resistance of cells. The result indicated that high resistance existed in the interfaces of cell with cowberry extract as sensitizer.更多还原