卷对卷印刷制备大面积钙钛矿太阳能电池的活性层薄膜形貌调控研究

Since the first report in 2009, there has been an unexpected breakthrough and rapid evolution of highly efficient organic-inorganic hybrid solar cells based on organometal trihalide perovskite materials (CH3NH3PbX3, X = Cl, Br, I). This technology has the potential to produce solar cells with the very highest efficiencies, while retaining the very lowest cost. The power conversion efficiency (PCE) of small-size perovskite solar cells (PSCs) has already been over 20 %, and it shows greatly potential applications in the future. However, the PCEs are still very low for large-size PSC devices and modules. One of the big issues is how to fabricate high-quality, large-area perovskite thin film. We propose a four-year research program to study the fabrication of high-quality, large-area perovskite thin film using roll-to-roll (R2R) printing techniques and its application in planar heterojunction PSCs. Focusing the morphology control of R2R printed large-area perovskite thin film, the formation process and mechanism of printed perovskite thin film, as well as the influence factors, would be disclosed through studying the printable perovskite inks materials, ink rheology, and printing parameters. The objective of our experimental program is to resolve the fundamental issues and challenges regarding the morphology control of R2R printed large-area perovkite thin film. Furthermore, the PCEs over 16 % and 12 % would be obtained for small-size (smaller than 1 cm2) and large-size (10 cm2) PSCs, respectively, using R2R printed high-quality perovskite thin film. These factors are essential for a timely progress in the proposed work and strong impact in the field of PSCs. Also, they will definitely accelerate the development and commercialization of PSCs.

有机铅卤化物钙钛矿（CH3NH3PbX3, X=Cl, Br, I）太阳能电池近三来获得了重大进展，小面积钙钛矿太阳能电池的效率突破了20%，表现出极大应用前景。但是大面积钙钛矿太阳能电池的效率依然偏低，其关键挑战在于如何制备出高质量的大面积钙钛矿活性层薄膜。本申请项目拟采用卷对卷印刷技术制备出可应用于平面异质结钙钛矿太阳能电池的大面积、高质量、柔性钙钛矿活性层薄膜，聚焦印刷制备的大面积钙钛矿薄膜的形貌调控这一关键基础科学问题，通过可印刷钙钛矿墨水材料、墨水流变性能、印刷制备参数等深入研究钙钛矿薄膜的印刷成膜过程及影响因素，揭示卷对卷印刷钙钛矿薄膜的形貌调控机制及形貌结构与墨水材料、流变性能、印刷制备参数等之间的关联，基于卷对卷印刷的柔性钙钛矿活性层薄膜制备的小面积（小于1cm2）太阳能电池效率超过16%、大面积（10cm2）太阳能电池效率达到12%，加快推进钙钛矿太阳能电池的产业化进程。

本项目研究聚焦印刷钙钛矿薄膜及太阳电池器件，并扩展到印刷钙钛矿光电探测器等。通过可印刷钙钛矿墨水材料、墨水流变性能、印刷制备参数等深入研究钙钛矿印刷成膜过程及影响因素，揭示刮涂、狭缝涂布、微凹版印刷（特别是卷对卷工艺过程）钙钛矿薄膜的形貌调控机制及形貌结构与墨水材料、流变性能、印刷制备参数等之间的关联，基于印刷技术在空气环境中制备的钙钛矿太阳电池光电转换效率达到了18%。通过界面调控和优化，柔性钙钛矿太阳电池效率达到19.51%（当时最高效率）；最近又获得了效率超过21%（第三方验证效率达到20.5%）的柔性钙钛矿太阳电池。在此基础上，构建了大面积钙钛矿太阳电池小型组件（18.9 cm^2），效率达到14%，研究成果为印刷制备大面积、高效率、柔性钙钛矿太阳电池提供了重要参考，将加快推进钙钛矿太阳电池从实验室逐步进入产业化。本项目达到了预期研究目标，累计在Adv. Energy Mater.、Adv. Funct. Mater.、Sci. Bull., APL、Nano Research等国际权威和重要期刊发表论文36篇，获授权发明专利9项，专利技术转让4项；组织举办了柔性印刷光电材料与器件国际会议1次；培养博士4人、硕士10人、博士后2人；项目负责人入选了湖南省领军人才计划、国家万人计划青年拔尖人才。