结构调制的多功能二氧化钛纳米管及其在染料敏化太阳能电池中的应用

发布时间：2018-03-10 19:23

本文选题：二氧化钛纳米管　切入点：染料敏化太阳能电池　出处：《上海交通大学》2015年博士论文　论文类型：学位论文

【摘要】：二氧化钛纳米材料是当今使用最普遍的一种半导体材料,由于纳米结构具有多样性,在很多的应用方面都发挥着重要作用。尤其是在当今社会,能源短缺日益加剧,环境保护又刻不容缓,有关拥有清洁、可再生优势的太阳能电池的研究备受关注。染料敏化太阳能电池(dye-sensitised solar cells,DSSCs)在诸多种类中相对来说,成本低廉,制备又不复杂,随着第三代太阳能电池发展至今,已经取得了丰富的研究成果。光阳极结构一向是染料敏化电池中重要的组成部分,而TiO_2是这一部分选材的首选,所以其一直受到人们的关注,也在不断地发展与创新。TiO_2纳米材料在DSSCs中,主要作为吸附染料敏化分子的载体,进而将光生电子传输给外电路。由于纳米管等一维纳米结构相比于纳米颗粒结构在电子传输等性能方面有着非常明显的优势,所以作为研究最广泛的光阳极材料,这种一维结构因其优秀的特性而备受关注。有关DSSCs中光阳极的科研工作,主要是探讨以下几方面:(1)、制备具有更大比表面积的光阳极结构、(2)、提升电子在半导体材料中的传输效率以及(3)、提高染料对光的捕获等几个重点研究方向。本论文的主要工作是围绕TiO_2纳米管(NT)材料的结构进行调制,在获得高性能的染料敏化电池的同时,研究发现NT的多功能性。详细的研究内容主要如下:1)NT在染料吸附量上相比于纳米颗粒有很大的缺陷,针对这一缺点,我们希望制备出具有大比表面积的更小管径的管子,利用水浴法升高阳极氧化反应的温度,可以获得管长长度达16μm、管径75 nm的高比表面积的纳米管薄膜。大长径比的二氧化钛纳米管薄膜的成功制备,为其在DSSCs的光阳极结构中的工作状态增加了很多优势,由于染料吸附量的显明升高,无论是电池的效率,还有电池性能,都有了大幅度的改善和提高。2)小管径纳米管薄膜由于其晶粒较小,更易受到基底效应的影响而在正常退火温度下产生金红石结晶态,这对DSSCs各方面的性能表现都会产生负面作用。所以为制备出具有纯锐钛矿晶型的小管径的管子,采用了低温退火后自剥离的方法。利用这种方法不仅可以保持纳米管薄膜的形貌不受破坏,同时还不引入基底效应的影响进而避免了金红石晶型的产生。最后通过实验对比可发现,小管径TiO_2纳米管,如果其为纯锐钛矿晶型,那么相比于含有金红石晶型的,在电池的效率及电子传输性能方面都更为优秀。3)为提高染料敏化电池的效率,合理的利用光散射层可以起到十分有利和显著的作用。利用大电压制备的接近可见光波长的大管径纳米管阵列作为光散射层,其散射作用相比于普通管径的纳米管阵列,有着明显的优势和发展潜力。在SEM分析了大管径纳米管薄膜的形貌后,将其作为光散射层,添加在DSSCs的光阳极上表面上,与无散射层、普通纳米管做散射层等结构进行了性能上的比较和分析,通过模拟和实验等多种角度证明了对于二氧化钛纳米管薄膜拥有这样的大管径确实具有非常优秀的散射作用。4)基于前期的实验工作,结合大管径的散射优势,合成出双层TiO_2纳米管薄膜,其上下两层的管径、管长均不同。利用其高温退火后的薄膜与纳米颗粒层的叠加组合,构成多层光阳极结构,使其同时拥有染料吸附层、电子传输层、光散射层等诸多功能。并且通过对多层光阳极中各层厚度的优化研究和分析比较,可以获得具有最优效率的染料敏化电池,相比于仅含纳米颗粒层,或者纳米颗粒与纳米管构成的双层组合,最高的情况为6.52%。
[Abstract]:The use of titanium dioxide nano material is a semiconductor material most commonly, because nano structure diversity, plays an important role in many applications. Especially in today's society, the growing shortage of energy, environmental protection and the urgent, have clean, renewable solar cell research advantage of the dye concern. The dye-sensitized solar cells (dye-sensitised solar cells, DSSCs) in many kinds of relatively low cost, the preparation is not complex, along with the development of the third generation solar cells so far, has made great achievements. The photoanode structure always is an important part in DSSC, while TiO_2 is the part of the material first, it has attracted people's attention, but also in the continuous development and innovation of.TiO_2 nano materials in DSSCs, mainly as adsorption of dye sensitized points Sub carrier, then the photogenerated electrons transmitted to the external circuit. Because the nanotubes of one-dimensional nano particles compared to the structure in the electronic transmission performance has obvious advantages, so as to study the light anode material most widely, this kind of one-dimensional structure because of its excellent optical anode and concern. The research work of DSSCs, mainly discusses the following aspects: (1) preparation, has the larger surface area of the anode structure, (2), enhance the transmission efficiency of electron in a semiconductor material (3), and improve the dye to capture several key research direction of the light. The main work of this paper is around TiO_2 nanotubes (NT) material structure for modulation in dye sensitized cell to obtain high performance at the same time, the study found that the versatility of NT. The detailed contents are as follows: 1) NT in dye adsorption amount compared to nano The particles have a lot of defects, to overcome this drawback, we hope that the preparation of smaller diameter with a large surface area of the tube, elevation of oxidation reaction using water bath temperature high, can obtain the length of length 16 m, diameter 75 nm high surface area. Nanotube films prepared with large ratio of length to diameter the titania nanotube films, added a lot of advantages in light anode structure in the DSSCs state, because the dye adsorption capacity obviously increased, both the efficiency of the battery, and battery performance has been greatly improved and improved.2) small diameter nanotubes film because of its smaller grain, more susceptible to the substrate effect arising from rutile crystalline in normal annealing temperature, the various aspects of the DSSCs's performance will have a negative effect. So for the preparation of the pipe diameter of the tubular with pure anatase,. With the method of self stripping after low temperature annealing. Using this method can not only keep the morphology of nanotube films is not damaged, but also does not influence the effect of introducing substrate and avoid the rutile crystal. Experiments can be found in small diameter TiO_2 nanotubes, if it is pure anatase, then compared to the contains rutile, in terms of efficiency and the electronic transmission performance of battery is better.3) in order to improve the efficiency of DSSC, the light scattering layer reasonable can play a very favorable and significant role. The use of high voltage preparation is close to the wavelength of visible light and large diameter nanotube array as the light scattering the scattering effect of nanotube array layer, compared to the ordinary diameter, has obvious advantages and development potential. In the SEM analysis of the morphology of large diameter nanotubes, as the light scattering Add in light anode layer, the upper surface of the DSSCs, and the scattering layer, ordinary nanotubes scattering layer structure are compared and analyzed on the performance, through various simulations and experiments proved that size has very good effect of.4 scattering for titania nanotube films have a large early experimental work) based on the combination of advantages of scattering size bassoon, synthesized double TiO_2 nanotube film, the two layer of the diameter, length are different. Using the combination of thin films and nano particles after high temperature annealing layer, a multi layer optical anode structure, which also has a dye layer, electron transport layer, many functions the light scattering layer. And through the comparison and analysis of the optimization of the thickness of each layer of multilayer optical anode, can obtain the DSSC with optimal efficiency, compared to only containing nano particles or layers. The combination of nanoscale nanoparticles and nanotubes is the highest of 6.52%.

【学位授予单位】：上海交通大学
【学位级别】：博士
【学位授予年份】：2015
【分类号】：TQ134.11;TM914.4

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