适用于卷对卷工艺的高效大面积柔性钙钛矿太阳能电池研究

Highly efficient large area flexible perovskite solar cells will be investigated by using scalable fabrication methods that are applicable to the roll-to-roll processing. High quality transitional metal oxides nanoparticles will be firstly synthesized by liquid chemical methods and their photoelectric properties can be controlled by doping and surface modification. Then, these nanoparticles will be used to prepare nanoparticle suspensions and composite sols by adding suitable additions, so as to achieve large area and scalable deposition of uniform carrier transport layers. Based on developing novel steady uniform perovskite ink, scalable manufacturing of the large area perovskite films on flexible substrates will be investigated by either screen printing or roll-to-roll coating process. Furthermore, the composition, shape and interface engineering of the carrier transport layers and the perovskite film layer will be optimized, so as to lower internal carrier recombination of the solar cell devices and thus improve the photoelectric conversion efficiency of the as-fabricated devices. Finally, the bending failure mechanism of the flexible perovskite solar cells will be revealed by analyzing the internal mechanical properties and exploring fatigue mechanical phenomenon of the devices. Along this line, the device structure and the preparation process of these functional film layers will be optimized, aiming to advance the photoelectric conversion efficiency of the flexible perovskite solar cells. In summary, the successful implementation of our project will provide theory and technology support for fabricating stable and flexible large area perovskite solar cells, and all these efforts also can greatly push the industrialization of the flexible perovskite solar cells, and thus the social and economical effect of the technology can be foreseen.

本项目拟开展可适用于卷对卷成膜工艺的高效大面积柔性钙钛矿太阳能电池应用基础研究。通过化学液相法制备高质量过渡金属氧化物纳米晶颗粒，通过对这些纳米颗粒的掺杂和表面改性，实现对其光电性能的调控；通过选取合适的溶剂和助黏剂，开发适用于大面积和规模化制备的均匀稳定载流子传输层纳米颗粒悬浮液或复合溶胶；通过开发均匀稳定的新型纳米晶钙钛矿油墨，结合丝网印刷或卷对卷制备工艺在柔性衬底上实现大面积钙钛矿薄膜的规模化制造；通过对载流子传输层和钙钛矿层的组分、形状、和膜层界面间的优化，以降低电池内部载流子复合率，从而提高电池器件光电转换效率；通过对柔性太阳能电池的内部力学性能分析，探索电池器件存在的力学疲劳现象，以揭示器件弯曲失效机制，依此改进器件结构设计，优化各功能膜层的制备工艺，从而提高柔性电池器件的光电转化效率。本项目的顺利实施将为今后规模化制备高效大面积柔性钙钛矿太阳能电池提供理论基础和技术支撑。

本项目从材料创新和电池结构设计入手，通过开发不同材料与结构的载流子传输层，以降低电池内部载流子复合率；通过开发适用于刮涂法的钙钛矿前驱体，实现了大面积钙钛矿薄膜的规模化制造。在此基础上制备了高效柔性钙钛矿电池，并通过对柔性器件弯折特性的研究，探索了柔性电池器件内部各功能膜层力学特性对电池弯折特性的影响机制。此外，还开展了钙钛矿电池滞回特性及其机制研究，以及混合卤素钙钛矿相分离特性研究。主要成果包括：.（1）开发了多种适用于柔性衬底的高效电子传输层制备方法，包括In2O3和SnO2等电子传输层，设计并制备了TiO2/In2O3，TiO2/SnO2，TiO2/PCBM等双层结构电子传输层，优化了界面能带结构并显著减少载流子的复合，取得器件光电转换效率18.85%。.（2）采用反溶剂法制备了基于低温碳电极电池器件，进一步通过在反溶剂中添加P3HT，实现了渐变钙钛矿异质结器件并获得15.57%的光电转换效率；开发了一种新型钙钛矿前驱体，可以在空气中通过刮涂法制备大面积钙钛矿薄膜，基于这种方法的碳基器件光电转换效率达15.62%。.（3）使用Cs0.02FA0.98PbI3钙钛矿材料作为光吸收层，同时使用富Cs+的Cs0.57FA0.43PbI3钙钛矿量子点旋涂在光吸收层之上，使电池器件获得了20.82%的高光电转换效率，且器件在30%湿度下放置300 h之后仍可保持90%的初始效率值。.（4）以SnO2为电子传输层在PEN-ITO衬底上制备柔性钙钛矿电池，获得了13.9%的光电转换效率；进一步制备了无空穴传输层的低温碳电极柔性器件，取得效率为11.53%，该器件经过2000次弯曲测试之后，其光电转换效率可保持为初始值的60%。.（5）以PET为衬底，采用自制PH1000薄膜为透明导电电极，制备的柔性电池器件效率达到9.49%。与基于PET/ITO衬底的器件相比，该器件的弯曲特性得到极大增强。通过有限元分析仿真发现，自制薄膜相较于ITO薄膜具有较小的Mises等效应力值，因此可有效提高柔性器件的机械弯曲性能。.本项目执行期间，项目成员共发表标注基金号SCI收录论文53篇（直接相关23篇和间接相关30篇），申请专利3项（已授权1项），培养研究生8名（博士生和硕士生各4名）。