发展环境友好的全无机非铅钙钛矿材料，对于促进钙钛矿太阳能电池的实际应用有非常重要的意义。但目前CsSnI3、CsGeI3等无机非铅钙钛矿材料存在相稳定性不佳和易氧化的瓶颈问题，不仅给电池的长期稳定性带来巨大挑战，同时晶格中产生大量空位缺陷导致严重的载流子复合和电池过低的开路电压。针对上述问题，综合Sn-Ge合金钙钛矿和材料量子化在提高钙钛矿相稳定性、化学稳定性方面的优势，提出研究发展光电性质优异、稳定性更好的CsSnxGe1-xI3钙钛矿量子点。项目将首先获取高质量CsSnxGe1-xI3量子点的可控制备方法，系统研究Sn/Ge比例和表面物化性质对钙钛矿结构、稳定性和光物理性质的调变规律；揭示量子点之间、量子点与电子（空穴）传输层界面的电荷输运动力学；构筑电池器件，建立量子点光物理性质-电荷输运-电池器件性能的内在关联。项目实施对于推动高效稳定全无机非铅钙钛矿电池的发展具有指导意义。

The development of environment-friendly all-inorganic lead-free perovskite materials is of great significance for the practical application of perovskite solar cells. However, current potential inorganic perovskite materials, such as CsSnI3 and CsGeI3, are facing the core problems of poor phase-stability and easy to be oxidized, which not only brings great challenges to the long-term stability of devices, but also causes a large number of vacancy defects in the lattice, thus leading to serious carrier recombination and low open-circuit voltage. To address above issues, we propose to develop CsSnxGe1-xI3 perovskite quantum dots with excellent photoelectric properties and better stability, after considering the advantages of alloyed Sn-Ge perovskite and material quantization in improving the phase stability and chemical stability of perovskite. This project will firstly study the controllable synthesis of high-quality CsSnxGe1-xI3 quantum dots. Effects of surface physical and chemical properties as well as Sn/Ge ratio on the perovskite structure, stability, and photophysical properties will be studied. The charge transport dynamics among quantum dots as well as the interfaces between quantum dots and electron / hole transport materials will be revealed. Then, CsSnxGe1-xI3 quantum dots solar cell will be prepared. The intrinsic relationship between the photophysical properties of quantum dots, charge transport as well as the device performance will be established. This project will promote the development of high-efficient and stable all-inorganic lead-free perovskite solar cells.