全无机钙钛矿太阳能电池界面能量损失的微区机制研究

钙钛矿材料的光吸收强、载流子迁移率高寿命长、激子束缚能低、材料及制备成本低廉和带隙可调等优点使得大带隙（大于1.65 eV）钙钛矿太阳电池可用于构筑硅基叠层电池，进一步提升硅基光伏器件效率和降低发电成本。目前应用于叠层电池的大带隙钙钛矿材料主要为有机/无机杂化钙钛矿，其面临热稳定性和光致相分离等影响器件性能的问题。CsPbI3全无机钙钛矿材料在带隙适用于硅基叠层电池的基础上具备更好的热稳定性且不会产生相分离。然而CsPbI3太阳电池由于较大的界面能量损失，其性能低于同带隙的有机/无机杂化钙钛矿器件。因此本项目拟在微观尺度上通过原位表征的方式探求CsPbI3薄膜界面能量损失与表面性质的内在关联，结合理论模型揭示界面能量转换损失的来源与机制。在此基础上，设计相应的组分工程和界面钝化方案，协同解决能量转换损失问题，并进一步探索界面性质对器件稳定性的影响，实现高效稳定的全无机钙钛矿太阳电池。

Perovskite materials have the advantages of strong light absorption, high carrier mobility, long carrier lifetime, low exciton binding energy, tunable bandgap and low cost of material and processing, which make the large bandgap (greater than 1.65 eV) perovskite solar cells and silicon solar cells can be combined to build tandem cells for improving the efficiency of silicon-based photovoltaic devices and reducing the power generation costs. At present, the perovskite tandem solar cells are mainly based on the large bandgap perovskite materials, which face the issues of thermal stability and photoinduced phase separation. The inorganic CsPbI3 perovskite material, which has the suitable bandgap for perovskite/Si tandem solar cell, possesses the better thermal stability without photoinduced phase separation, and thus is a promising alternate for perovskite/Si tandem solar cell. However, CsPbI3 solar cells have lower photovoltaic performance than the organic/inorganic hybrid counterpart with the same bandgap due to larger interfacial energy loss. Therefore, this project intends to explore the intrinsic relationship between the interfacial energy loss and the surface properties of the CsPbI3 film through in-situ characterization on a microscale, and then combine the theoretical model to reveal the source and mechanism of energy conversion loss at the interface. Based on these results, the corresponding solutions for component engineering and interfacial passivation can be designed to address the issues of interfacial energy loss. Then, the effects of interfacial properties on the device stability will be explored to achieve high-efficiency and stable all-inorganic perovskite solar cells.