混合阳离子钙钛矿太阳能电池光电机理的研究

Photoelectricity mechanism of mixed cation perovskite solar cell

掺杂改性对钙钛矿晶体结构演化以及薄膜的光吸收性能有很大影响,并直接决定了钙钛矿太阳能电池的性能。采用一步溶液法制备了钙钛矿太阳能电池器件,分别研究了阳离子掺杂对钙钛矿晶体结构、晶体缺陷与器件光电性能的影响。研究表明,甲脒基(FA)及Cs离子掺杂改善了钙钛矿的成膜性以及薄膜的表面形貌。同时,阳离子掺杂有效降低了钙钛矿晶体的缺陷密度,这源于FA及Cs离子的取代掺杂有效促进了钙钛矿相的形成,避免了二次相的产生,并因此改善了钙钛矿薄膜表面形貌。器件的光电转化效率由10.29%提升至12.49%。

The mixed cation doping has a great impact on the structure evolution and light absorption of perovskite film, which directly determined the performance of perovskite solar cells. Perovskite solar cells were fabricated by one-step method and the effect of cation doping on the crystal structure, defects and the photoelectric property of devices were subsequently investigated. The result shows that the structure and the surface morphology of perovskite layer can be evidently optimized due to the doping of FA and Cs ions. Meanwhile, the cation doping decreases the amount of the defects in perovskite crystals, which is attributed to the fact that the cation substitution doping of FA and Cs ions in the MAPbI3 can effectively promote the formation of the perovskite phase, thereby inhibit the secondary phase and significantly improve the surface morphology of the perovskite film. As a result, the mixed cation doping remarkably increased the photoelectric conversion efficiency(PCE) of the device from 10.29% to 12.49%.