【作者】 胡浩；

【导师】 赵兴中；

【作者基本信息】 武汉大学 ， 微电子学与固体电子学， 2011， 博士

【摘要】 本论文研究的主要内容包括：对于绿色制备铂的纳米颗粒以及负载铂的碳材料对电极的研究；探讨二氧化钛的水凝胶改性碳材料对电极对于染料敏化太阳能电池的光电转换效率以及稳定性的影响;以及对于新型石墨烯气凝胶材料对电极的探索。取得主要研究成果如下：1、优化基于碳材料对电极的染料敏化太阳能电池的工艺参数。对于我们所研究的碳材料对电极体系而言,使用炭黑和石墨质量比为1：3时,其组装的染料敏化太阳能电池的光电转换效率最好；同时当羟乙基纤维素的质量占碳材料质量的2.5%时,碳材料对电极组装的染料敏化太阳能电池的光电转换效率最好,可达5.60%。2、研究了一种铂的纳米颗粒的制备方法,该方法具有简单、快速、绿色等优点。将这种所制备的铂的纳米颗粒应用碳材料对电极之中,可以在很大程度上减少铂的使用量。由碳／铂复合对电极组装的染料敏化太阳能电池,其光电转换效率可达6.42%,与普通碳材料对电极组装的器件相比,其光电转换效率提高了12%。3、研究了一种使用铂的纳米颗粒制备的碳材料对电极。通过测试这种负载铂的碳材料对电极的方块电阻,表明其具有较好的导电性能；通过对其进行循环伏安测试表征,表明其对于I-/I3-氧化还原电对具有良好的催化性能；通过由不同含量的负载铂的碳材料对电极组装的染料敏化太阳能电池的具体性能参数的对比,寻找到了一个最少的铂的用量,即使用1.0wt%的铂的纳米颗粒即可达到器件性能的最大收益,染料敏化太阳能电池的光电转换效率可达6.4%。这种简单的、环境友好型的制备碳材料对电极的方法,使得染料敏化太阳能电池的成本大幅度降低,有利于染料敏化太阳能电池的实际应用。4、研究了一种稳定的碳材料对电极的制备方法。通过在碳材料对电极浆料中引入二氧化钛的水凝胶,制备碳／二氧化钛水凝胶复合对电极。经过导电性测试,碳／二氧化钛水凝胶复合对电极比普通碳材料对电极具有更加好的导电性；在电化学催化活性方面,二氧化钛这种宽禁带半导体材料的引入,对于碳材料对电极的电化学催化活性没有明显的影响。具体来说,碳材料对电极对于I-3/I-这个还原反应的催化能力没有明显的影响；而且在另一方面,由碳/二氧化钛水凝胶复合对电极组装的染料敏化太阳能电池,其光电转换效率和长程稳定性等性能都比由普通碳材料电极组装的染料敏化太阳能电池要好。对于染料敏化太阳能电池性能的提高,其主要原因来自于二氧化钛的水凝胶的引入,二氧化钛的水凝胶经过退火之后形成二氧化钛纳米颗粒,这些二氧化钛纳米颗粒在碳材料对电极中起了两个重要作用：1、在碳材料颗粒之间起到了桥联作用；2、在碳材料颗粒与FTO导电玻璃衬底之间起到了粘结作用。由碳/二氧化钛水凝胶复合对电极组装的染料敏化太阳能电池,其最好的光电转换效率为6.3%,而由普通碳材料电极组装的染料敏化太阳能电池,其光电转换效率为5.8%。5、研究了一种新型材料-石墨烯气凝胶的制备、并对其进行表征。通过拉曼光谱测试、扫面电子显微镜测试以及能量色散谱测试,证明了所制备的产物为石墨烯气凝胶；通过BET测试,定量的得到了石墨烯气凝胶的比表面积；通过循环伏安测试,了解了石墨烯气凝胶的电化学性能；最后,我们将石墨烯气凝胶应用于染料敏化太阳能电池的对电极之中,其器件的光电转换效率为1.43%。更多还原

【Abstract】 In this thesis, we have systematically studied the green synthesis of platinum nanoparticle and its application in low-Pt loading carbon counter electrode (CE); the stability of Ti-hydrogel modified carbon counter electrode; the novel counter electrode based on grapheme aerogel and its application in dye sensitized solar cell (DSSC). The main results and achievements are as following:1. Optimizing the parameters of the DSSC assembly process based on carbon counter electrode, In our research system, adding carbon black and graphite at the weight ratio of1:3in the carbon paste, the DSSC based on the as prepared carbon CE has the best performance. On the other side, adding the hydroxyethyl cellulose at the weight ratio of2.5%, the device showed the best power conversion efficiency (5.6%).2. We report a rapid and effective green chemistry route of the synthesis of Pt nanoparticles (PtNPs). Under optimized conditions, the PtNPs were found to distribute uniformly in a narrow size range of3.6to4.1nm and exhibit high stability in the colloids. In addition, these nanoparticles, having advantages of high surface area, narrow distribution and mono-dispersivity, were applied to enhance the catalytic activities of low-cost carbon based CEs for DSSCs. Consequently, the efficiencies of the cells showed a promising improvement from5.7%(of a typical carbon CE) to6.4%by using the carbon/PtNPs composite CE.3. A6.4%high efficiency Pt/carbon electrode was used in DSSCs with combination of low-cost, low Pt-loading and easy-fabrication. The effect of Pt content in carbon counter electrodes and the corresponding performance of DSSCs were investigated. Electrochemical measurement indicated that the optimized Pt content was1.00wt%and the catalytic activity of Pt/carbon counter electrode was saturated in device at this content. Low Pt-loading and high efficiency highlight the potential application of this Pt/carbon counter electrode in low-cost DSSC.4. We described a systematic investigation of the stability of a carbon/TiO2 counter electrode for use in DSSCs. In this system, nanoparticle additives were introduced by adding Ti-hydrogel. The additives then bound carbon particles and enhanced the adhesion of carbon materials to the conductive substrate. After introducing the Ti-hydrogel into the carbon paste, the carbon/Ti-hydrogel composited counter electrode (HC-CE) showed a better conductivity and stability compared with that of the carbon counter electrode (C-CE), while the catalytic activity was not influenced. The device based on the HC-CE showed superior power conversion efficiency (6.3%) and long-term stability over the device based on the C-CE (5.8%).5. A novel carbon CE were fabricated with graphene areogel. Though the Raman, SEM and EDS test, the product have been proved to be the graphene areogel. The as prepared graphene has large surface area though the BET test. However, the catalytic activity of this graphene areogel towards I-/I3-redox was limited. The DSSC based on this graphene areogel CE showed power conversion efficiency of1.43%.更多还原