课题组与武汉理工大学材料复合新技术国家重点实验室、佛山仙湖实验室的李蔚研究员在Cell Press细胞出版社旗下期刊Joule上发表了一篇题为“Organic-inorganic hybrid nature enables efficient and stable CsPbI₃-based perovskite solar cells”的研究论文。该研究在国际上首次从微观尺度揭示了DMAI辅助法制备的无机“四方相CsPbI₃”实际上是有机-无机杂化四方相(DMA, Cs)PbI₃。https://doi.org/10.1016/j.joule.2023.10.019

CsPbI3-based perovskite solar cells (PSCs) have attracted intense research interest since the inorganic absorber layer has better thermal stability compared with hybrid perovskites. However, CsPbI3 suffers from structural instability due to an easily induced phase transition from the photoactive phase to the photoinactive phase. Introducing (CH3)2NH2I (dimethylammonium iodide [DMAI]) into the CsPbI3 precursor solution stabilizes the tetragonal (b-phase) of CsPbI3, but there is still debate about whether DMA+ is incorporated in the perovskite structure. Here, we report unambiguous evidence for the formation of tetragonal (b-) (DMA, Cs)PbI3 by substituting the small ionic radius Cs+ with the large organic cation DMA+. The organic-inorganic hybrid b-(DMA, Cs)PbI3 shows a better optoelectronic properties than inorganic orthorhombic (g-phase) CsPbI3. Consequently, PSCs based on b-(DMA, Cs)PbI3 exhibit a champion power conversion efficiency of 19.76%. These observations suggest that hybrid b-(DMA, Cs)PbI3, with a dominant inorganic composition, is preferable compared with inorganic g-CsPbI3 for efficient and stable PSCs.