新型太阳能电池材料CH3NH3PbX3（X=Cl，Br，I）的晶体生长和性能研究

Organic-inorganic hybrid perovskite-structured materials exhibit advantages such as low cost, high photoelectric conversion efficiency, and low temperature solution synthesis feasibility, making them the basis materials for developing the new generation high-efficient solid-state solar cells. In order to optimize the performance of halide perovskites CH3NH3PbX3 based solar cells and to promote their commercial applications, we propose in this project to grow CH3NH3PbX3(X = Cl, Br, I or a combination) crystals by the solution method, study the crystal growth kinetics, determine the crystalline habits and explore the growth mechanism. The studies on physical and chemical properties, electrical properties, optical and photoelectronic performances will be systematically carried out, and the mechanism problems will also be revealed. By optimizing crystal growth parameters, high-quality and large-size CH3NH3PbX3 (X= Cl, Br, I) single crystals and certain-size mixed-halide perovskite single crystals are expected to be obtained. The study results based on the crystal growth, their structural and property characterization, will be used for guiding the fabrication of the novel perovskite-based solar cells. In summary, this project aims at the development of novel organic-inorganic hybrid perovskite-structured materials, for promoting the integration of basic science and applied research, and making the initial innovation in this field. In addition, it will also accelerate the industrialization applications of the novel high efficiency solid-state solar cells, and enhance the competitive ability of our country in solar cell industry.

有机－无机杂合卤化物钙钛矿结构材料因成本低，光电转化率高及溶液低温工艺等优势将成为新一代高效全固态太阳能电池的基础材料。为优化卤化物CH3NH3PbX3钙钛矿基太阳能电池的性能、促进其商业化应用，本项目采用溶液法生长CH3NH3PbX3 (X=Cl,Br,I 或混合卤素) 单晶，通过晶体生长动力学研究，明确结晶习性，探索生长机理。系统地研究其物化性能，电学、光学性能及光电转化性能等，揭示机理问题。通过优化晶体生长工艺，获得优质大尺寸CH3NH3PbX3(X=Cl,Br,I)单晶和一定尺寸的混合卤化物单晶。基于晶体生长，结构与性能的研究，将为新型钙钛矿太阳能电池的研制提供理论指导。这项工作弥补了国内外有机－无机杂合卤化物钙钛矿结构单晶生长技术及性能研究的不足，有助于促进基础研究和应用研究的一体化和源头创新；对推动新型高效全固态太阳能电池的产业化，提升我国在光伏领域的研发竞争力具有重要意义。

有机—无机杂化钙钛矿CH3NH3PbX3材料因成本低、溶液低温制备工艺、优异的光电性能等优势在新型高效全固态太阳能电池、光电探测、发光领域等展示出良好的应用前景。为了优化钙钛矿太阳能电池的性能，解决制约其发展的瓶颈问题，生长CH3NH3PbX3晶体，研究其基础性能及应用具有重要意义。.首先，采用溶液法生长CH3NH3PbX3及混合卤素钙钛矿系列晶体，并实时研究晶体生长动力学。另外，提出采用超薄液层液相外延生长二维CH3NH3PbX3钙钛矿晶体的方法。其次，采用现代分析测试技术对上述样品的晶体结构、物化性能、电学性能、光学性能及光电性能等进行了表征，获得重要的基础性能参数；结合第一性原理计算，提出表—界面工程是提高钙钛矿太阳能电池性能的有效途径之一。最后，为克服杂化钙钛矿材料环境敏感的缺点，提出低成本、实现高效杂化钙钛矿晶体封装工艺，该工艺能够提高材料稳定性，延长器件使用寿命。.研究结果表明晶体生长工艺对于晶体的生长习性与微观形貌影响显著；能带工程是设计新材料有效途径，不同卤族元素的配比能够调节钙钛矿晶体能带结构；二维钙钛矿晶体具有独特的晶体结构和物化性能；密度泛函计算作为研究钙钛矿CH3NH3PbX3晶体性能、材料设计、晶体生长机理和器件优化的有效途径，帮助我们在分子层面理解设计钙钛矿；不同类型的杂化钙钛矿晶体对于可见光波段的高相应度、光生载流子高迁移率、载流子电极高收集、浅层缺陷能级等优良光电性能，决定杂化钙钛矿晶体成为一种优质的光电功能材料。.本项目执行期间，制备得到厘米尺寸的CH3NH3PbX3(X＝I，Br，Cl)、CH3NH3SnI3和混合卤素CH3NH3Pb(IBr)3 、CH3NH3Pb(BrCl)3 、CH3NH3Pb(ICl)3晶体，获得微米尺寸、纳米级厚度的二维CH3NH3PbX3晶体；发表SCI论文25篇，专利成果7项，其中5项发明专利、1实用新型专利已经授权，1项发明专利实现成果转让。参加国内、国际会议8次，作口头报告4次。获得江苏省教育厅自然科学三等奖一项，培养硕士研究生3人，在读硕士研究生2人。.本项目的研究结果被国内外多次引用，晶体尺寸达到国内外较高水平。这项工作为生长钙钛矿型晶体提供工艺参考，为优化有机—无机杂化钙钛矿太阳能电池的性能提供理论依据；同时，这项工作也为拓展钙钛矿晶体的应用，发展新型高效钙钛矿光电器件打下一定的材料基础。