高稳定芳香胺多量子阱钙钛矿材料与发光器件研究

Organic/inorganic hybrid perovskites show tremendous application potential in the low-carbon lighting and display fields due to its high luminescence efficiency and low cost. However, the further development of perovskite light-emitting devices is still limited by its low stability. The main reason arises from the migration of small sized organic cations under the impact of environment during device operation, which can trigger the decomposition of perovskites. This project is proposed to demonstrate the inherent relationship between the structural tuning of perovskite materials and their stability. The stable aromatic ammonium cations will be incorporated to achieve the structural tuning of multiple quantum wells (MQWs) based perovskites. The packing of the aromatic amine in the internal structure of MQWs can block H2O into their lattice, inhibit the migration of other small sized organic cations, and enhance their thermal stability. By investigating the relationship between the structure of MQWs and stability of their devices, high-stability MQWs based aromatic ammonium perovskite devices can be obtained. The project will provide therotical and technical guides for the commercialization of perovskite light-emitting diodes.

有机/无机杂化钙钛矿发光材料因成本低廉、发光高效，在“低碳”照明与显示领域展现出巨大的应用潜力。然而，稳定性差成为制约钙钛矿光电器件发展的瓶颈，其主要原因在于钙钛矿内部有机胺离子易受光、水等环境影响发生迁移，导致器件性能快速退化。前期研究表明，引入大尺寸有机胺离子对钙钛矿结构进行调控，有望解决这一难题。本项目拟围绕钙钛矿结构调控与其稳定性的内在关联这一关键科学问题，引入高稳定多环芳香胺离子，实现钙钛矿的多量子阱结构调控。通过芳香胺多环递增紧密堆积，阻隔水分子进入其晶格、抑制有机胺离子迁移、增强其热稳定性，构筑高效稳定钙钛矿发光器件。阐明芳香胺多量子阱钙钛矿结构与器件稳定性的构效关系，为高稳定钙钛矿发光器件商业化推广提供新的思路和技术支撑。

为了阐明多量子阱钙钛矿材料的构效关系，实现高稳定多量子阱钙钛矿发光器件，本项目通过分子结构设计，制备了系列芳香胺基多量子阱钙钛矿光电材料，并对其光电性能进行了研究，研究发现当芳香胺分子链长越短，钙钛矿量子阱垒宽越小，相应薄膜的电荷迁移率越高，其发光器件亮度达到30,000 cd m-2。通过真空减压退火方法，对芳香胺基多量子阱钙钛矿结晶过程进行调控，实现了维度裁剪，其钙钛矿LED的外量子效率（EQE）达到13%。我们进一步通过芳香胺添加剂调控钙钛矿结晶相变路径，实现了低温制备高性能钙钛矿薄膜策略，发光器件效率滚降现象得到明显抑制。通过以上研究，最终获得了提高器件效率和稳定性的系列芳香胺钙钛矿光电材料体系，为钙钛矿发光器件商业化推广提供新的思路和技术支撑。