基于p-i-n构型的平面异质结钙钛矿太阳能电池衰减机理及环境稳定性提升研究

The efficiency of perovskite solar cells is constantly rising, making it the most popular candidate in photovoltaic research filed. The planar heterojunction perovskite solar cells based on p-i-n configuration (i-PSCs) can be easily produced with large scale and low cost due to their advantages of low-temperature fabrication and compatibility with flexible substrate, and so on. Unfortunately, the stability of i-PSCs is very bad. The studies about the degradation mechanism and the enhancement of device stability are significant for its commercial application. In this project, we plan to overcome the problems of fast decay rate and the unclear influence of the single attenuation factor in i-PSCs device via designing the test fixture, and investigate the internal degradation mechanism of the proposed device by the real time (RT) analysis method. The degradation processes of the devices under individual or multiple influence factors will be explored. Combing with the law of material degradation and on the basis of previous research work, the interface decay mechanism of i-PSCs, and the interaction mechanism between materials decay and devices decay will be further discussed, and the intrinsic chemical and physical decay process in devices will also be revealed. All of these findings may provide a theoretical basis for understanding the degradation behavior of the devices and the fabrication of high efficient and stable perovskite solar cells. At last, we attempt to improve the stability of the devices based on interface modification via a selective inorganic nanopartice layer, which in turn provide the experimental support of the degradation mechanism.

钙钛矿太阳能电池效率不断攀升，已成为当今光伏研究领域最为热门的新星。基于p-i-n构型的平面异质结钙钛矿太阳能电池（i-PSCs）具有易于低温加工、可兼容柔性衬底等优点，最易实现大面积、低成本制备。然而其稳定性令人堪忧。研究器件衰减机理及提升器件稳定性对于其走向应用意义重大。本项目通过设计工装夹具，克服i-PSCs器件衰减速度过快和各衰减因素难以隔离研究的难点，通过实时分析手段对该类型器件内在衰减机理进行研究。主要探索在不同衰减因素单独或协同作用下器件的衰减过程。结合材料的衰减规律，在原有工作基础上，深入研究器件界面衰减行为，探索材料衰减与器件衰减内在作用机制，揭示器件内部物理化学衰变过程，为理解该类型太阳能电池衰减行为以及为构建高效稳定的钙钛矿太阳能电池提供理论基础。此外，从界面修饰角度，选择引入无机纳米粒子修饰层，构建稳定i-PSCs器件，为本项目衰减机理研究提供实验支撑。

器件衰减机理及提升器件稳定性的相关研究对于钙钛矿太阳能电池走向应用意义重大，本项目以p-i-n构型的平面异质结钙钛矿太阳能电池的衰减机理为主线，并以提升器件稳定性为最终目标。本项目在前期工作的基础上进一步优化了器件制备工艺，获得了高质量的钙钛矿薄膜与太阳能电池器件，设计了分因素太阳能电池衰减测试夹具，探索了器件在水、热、光等因素下的衰减机制以及他们之间的协同作用，证实了水诱导的界面衰减是器件衰减的主因。根据衰减机制，本项目利用疏水的无掺杂的PTAA以及设计合成碳基复合材料、多种金属氧化物为空穴传输层，成功提升了器件稳定性。此外，成功利用非富勒烯克服了PCBM成膜性问题，证实了非富勒烯材料在高效稳定p-i-n构型平面异质结钙钛矿太阳能电池制备中的独到优势。最后，针对晶界脆弱性对器件稳定性造成的不利影响，本项目利用晶界钝化策略，利用二甲氨基苯甲酸等钝化材料成功抑制了晶界缺陷态以及增加了晶界的稳定性，器件稳定性得到了提升并且效率达到了20 %以上。本项目的研究为p-i-n构型平面异质结钙钛矿太阳能电池衰减认知奠定了基础，为高效稳定的钙钛矿太阳能电池器件制备提供了重要的思路。