钙钛矿太阳能电池界面结构调控及其光、热稳定性研究

The power conversion efficiency of perovskite solar cells (PSCs) have recently attained 23%, exceeding the commercialized CIGS and CdTe solar cells. However, one of the major hindrances for real application of PSCs is the instability of perovskites, particularly under light and thermal conditions. This project focus on the material interface, as the main channel of degradation. Degradation process of perovskites under light irradiation and high temperature will be firstly investigated by theoretical calculation to reveal the control step of degradation process and identify the active sites. Then, we will develop new interface molecular engineering methods to passive the active sites by certain molecules based on the characteristics of surface local bonding of perovskites. The relationship between degradation rates and surface molecular structure, such as functional groups, types of chemical bonds and dielectric properties, will be systemically investigated by measuring the corresponding parameters, including ion migration and thermal decomposition. Surface molecular design principle for stabilizing hybrid perovskite materials will be established. Moreover, passivation molecules with multiple functional groups or polymers will be used to further enhance the photo- and thermal stability. Based on the above studies, this project will develop the advanced processing techniques of PSCs with low-cost, high efficiencies and long-term stability, which provide guidelines for design and engineering of interface of new photovoltaic techniques.

钙钛矿太阳能电池的效率现已突破23%，超过了市面上CIGS和CdTe等薄膜电池的水平，倍受科研界和产业界关注。然而其核心组件钙钛矿材料在光照、高温条件下的不稳定性，严重制约了其实用化进程。本项目从钙钛矿材料分解的关键位置——“界面”出发，通过理论计算模拟材料界面在光、热条件下分解行为，探明其分解的决速步骤和关键活性位点；基于材料界面近程成键特点，将多种分子和离子锚定、组装于界面分解活性位点，考察官能团种类、成键类型、介电特性等参数与界面处的离子移动、热损失等行为的内在关联，形成具有一定指导性的界面分子结构设计原则和调控策略；指导开发具有多重功能的多齿分子、聚合物等新型钝化材料，降低材料在光、热条件下的敏感性；进而构筑出多种低成本、高性能、稳定的新型钙钛矿太阳电池器件，为新型光伏器件的界面设计与结构调控提供可靠的实验依据和理论指导。

钙钛矿太阳能电池被认为是最有发展潜力的新一代光伏技术之一，具有效率高、原料成本低、易加工等优势。本项目围绕钙钛矿电池形成/退化机制、表界面结构原子尺度调控、及光伏电池构型设计等方面，开展了系统的理论与实验研究，为实现高效率钙钛矿太阳能电池商业化发展提供应用基础和理论依据。具体开展了以下三个方面的工作：（1）揭示钙钛矿材料形成及分解机制，建立高质量钙钛矿薄膜材料的制备方法；（2）开发了二硫代氨基甲酸盐、含氧酸盐、咪唑类离子液体等多种表面钝化功能材料，建立了钙钛矿表面功能分子定向组装的化学方法，实现对钙钛矿材料光、热稳定性的提升；（3）基于能级排列和载流子输运进行器件整体设计，开发出钝化/传输功能一体化的界面功能材料，建立稳定高效的钙钛矿太阳能电池制备工艺，实现了AM1.5G持续光照下的T80寿命超过4000小时的光伏器件。基于项目实施，在Nature Commun., Energy Environ. Sci., Adv. Energy Mater., Adv. Funct. Mater.等国际知名学术期刊发表标注有该项目资助的学术论文20余篇，申请4项中国发明专利。项目执行期间，项目负责人入选国家优秀青年基金、上海科技青年35人引领计划。圆满地完成了既定任务。