锡(IV)基非铅钙钛矿材料的设计合成及其在太阳电池中的应用研究

ABX3 metal halide perovskite solar cell has been regarded as an immense potential alternative for new generation solar cells for its fascinating advantages like high efficiency and low cost. However, the toxicity of generally selected lead element hampers its development in industrial application. Accordingly, the lead-free halide perovskite materials based on low-toxic tin(II) have been researched extensively as an alternative, which however, presents another challenge of being oxidized readily and showing low-lifetime of devices. Therefore, this project proposes to develop the stability lead-free solar cells via synthesizing A2BX6 stylistic perovskite materials like (CsxMAyFA1-x-y)2Sn(BraI1-a)6 in consideration of the high chemical stability of Sn(IV). This material is an ideal photoelectric functional material with suitable bandage and high carrier mobility. Specifically speaking, this project will in the first place employ the chemical vapor deposition (CVD) assistant to prepare large-grained films through adjusting the chemical composition and crystallization kinetics process. Secondly, the technology of Ultrafast Laser Spectroscopy et al. will be used to study the mechanism of defect formation and charge recommendation in materials. Afterward, an effective method will be developed to suppress the defect in materials and prepare high performance solar cells. In conclusion, the original innovation of this program manifests in exploiting and preparing the inventive low-toxic and stable Sn(IV) perovskite materials. Moreover, the mechanism of charge dynamics for these perovskite materials will also be studied in this program, offering theoretical guidance for their further application in optoelectronic devices. Hence, this research is of great scientific and practical value without any doubt.

ABX3型卤化铅基钙钛矿太阳电池具有高效率、低成本的优势，是一类极具潜力的新型太阳电池。然而铅的毒性妨碍其产业化应用，作为替代品低毒性锡(II)基钙钛矿材料被广泛研究，但是锡(II)易氧化的属性影响了器件寿命。基于锡(IV)的高化学稳定性，本项目拟开发组成为(CsxMAyFA1-x-y)2Sn(BraI1-a)6的A2BX6型钙钛矿材料，进而构建性能稳定的非铅太阳电池器件。该材料具有合适带隙、高载流子迁移率，是理想的光电功能材料。采用化学气相沉积（CVD）辅助的方法，调节材料化学成份，控制结晶生长过程，制备高质量大晶粒薄膜材料；利用超快光谱等技术，深入探究材料中缺陷产生与电荷复合机制，提出有效的缺陷抑制方法，实现高性能的太阳电池器件。本项目中低毒、稳定的锡(IV)基非铅钙钛矿材料开发是材料源头性的创新，通过电荷动力学机理研究为该材料应用提供理论上的指导，相关研究具有重要的科学意义。

高性价比太阳电池的开发与应用是解决目前能源与环境问题的有效途径。钙钛矿太阳电池是一种具有低成本、高效率潜质的光电转换器件，是下一代商业化太阳电池的有力竞争者，得到了广泛的关注与研究。本项目围绕着Sn(IV)基钙钛矿材料的开发与器件化应用展开，利用该材料高空穴迁移率的优点，将该材料作为空穴传输材料应用于碳基钙钛矿太阳电池研究，详细研究了其对电荷分离与提取动力过程的影响。结果表明，该类材料具有合适的能带结构，通过构建阶梯能加速空穴的分离与提取，进而减少非辐射损失，增强器件的光伏性能，相应的器件获得了最高14.67%的光电转换效率。另外，本项目的实施过程也针对碳基钙钛矿太阳电池的一些基础科学问题开展了系统的研究工作，在钙钛矿薄膜材料的制备与缺陷钝化、电子/空穴界面的修饰和兼容性碳电极制备等方面取得了阶段性的成果，为实现高效率高稳定性钙钛矿太阳电池器件提供了参考。本项目的研究内容与结果将有力推进钙钛矿太阳电池应用化的发展。