全钙钛矿相量子点敏化太阳能电池的组装与性能表征

In this project, the SrTiO3 array film, the CH3NH3PbI3 photosensitizer, and the solid electrolyte CsSnI3-xFx, which are all in perovskite phase, will be grown directily on FTO transparent conductive substrates through hydrothermal process, prepared by rotary evaporation in vacuo or dipping methods, and synthesized at high temperature, respectively. Considering the high photoelectrical activity and stability of CH3NH3PbI3 in the research of semiconductor photosensitization, the paritcle size of the sensitizer will be reduced until the generation of quantum size effect, and then the nanoparticles can be loaded onto the surface of SrTiO3 arrays as the quantum dots. Combined with the metallic Pt counter electrode, the sandwich shaped all-solid-state and all-perovskite-phase quantum dot sensitized solar cells (QDSCs) could be fabricated, containing these three kinds of materials in the same crystal phase as the working electrode, the sensitizer, and the electrolyte, respectively. The photoelectrical property such as the photoelectrical conversion efficiency and the cycling stability of this novel solar cell will be also tested and optimized, in order to get a new type of QDSCs with low cost, high efficiency, and high stability, which may lay the foundation for the practical application in the future.

本项目利用水热法在FTO导电玻璃上制备钙钛矿型SrTiO3阵列薄膜，利用真空旋蒸或浸渍法在SrTiO3薄膜表面负载钙钛矿型CH3NH3PbI3敏化剂，利用高温热合成法制备钙钛矿型CsSnI3-xFx。根据CH3NH3PbI3在半导体敏化研究中高光电活性以及高稳定性的特点，将敏化剂粒子尺寸缩小，直到能够产生量子尺寸效应，负载到SrTiO3阵列表面形成量子点。将相同晶型的三种材料分别作为新型敏化太阳能电池中的阳极、敏化剂和电解质组分，与Pt单质电极结合，组装三明治型层状全固态全钙钛矿量子点敏化太阳能电池，并对体系的光电转化能力及循环稳定性进行表征。通过不断优化器件的各项性能，最终得到低成本、高活性、高稳定性的新型固态量子点敏化太阳能电池，为满足生产生活的实际应用奠定基础及提供思路。

钙钛矿太阳能电池被认为是一类具有明朗应用前景和巨大应用潜力的新型光伏器件。项目开展期间，我们围绕钙钛矿太阳能电池及其相关领域开展了研究工作。本项目主要针对以SrTiO3为代表的无机非铅钙钛矿半导体材料，合成了从零维到三维的SrTiO3-TiO2纳米粒子/棒/管等一系列异质结型半导体材料，并将其应用于全固态钙钛矿/染料敏化太阳能电池的组装研究，器件的光电转化性能相比纯TiO2基太阳能电池有了很大提升。主要研究结果如下：.（1）首次使用三步原位水热法制备了异质结型SrTiO3-TiO2纳米管阵列，并组装成全固态染料敏化太阳能电池。SrTiO3对TiO2的修饰可有效降低半导体与光敏染料之间光生电子传输的阻力，光电转化效率相对于纯TiO2基太阳能电池提高了60%；.（2）在金红石型单晶TiO2纳米棒阵列表面均匀沉积了SrTiO3纳米粒子，并组装成全固态染料敏化及钙钛矿太阳能电池，电池效率相对于未经修饰的TiO2基电池都有了很大提升。这种方法特别适合大规模工业中碱性条件制备TiO2的生产改性；.（3）在涂有SrTiO3薄膜的导电基底上通过水热法生长一层花状的单晶TiO2纳米棒，并以TiO2/SrTiO3复合薄膜作为阳极材料组装成三明治型全固态染料敏化太阳能电池。和TiO2纳米棒相比，电池效率提高了1.6倍，而纯SrTiO3薄膜光照下几乎无响应；.（4）除了以钙钛矿修饰TiO2，我们还通过石墨烯负载、氮掺杂以及磁性铁固载等方式设计了一系列具有分散度高、径向生长能力强、对光响应范围广以及易回收等功能性TiO2光电及光催化材料，进一步提高TiO2基半导体材料的光电及光催化性能，拓展材料应用领域。