State Key Laboratory of Catalysis, Dalian National Laboratory for Clean Energy, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian, 116023, China.
University of Chinese Academy of Sciences, Beijing, 100049, China.
Nat Commun. 2023 Jan 17;14(1):256. doi: 10.1038/s41467-023-35837-1.
The low fraction of non-radiative recombination established the foundation of metal halide perovskite solar cells. However, the origin of low non-radiative recombination in metal halide perovskite materials is still not well-understood. Herein, we find that the non-radiative recombination in twinning-tetragonal phase methylammonium lead halide (MAPbICl) is apparently suppressed by applying an electric field, which leads to a remarkable increase of the open-circuit voltage from 1.12 V to 1.26 V. Possible effects of ionic migration and light soaking on the open-circuit voltage enhancement are excluded experimentally by control experiments. Microscopic and macroscopic characterizations reveal an excellent correlation between the ferroelastic lattice deformation and the suppression of non-radiative recombination. The calculation result suggests the existence of lattice polarization in self-stabilizable deformed domain walls, indicating the charge separation that facilitated by lattice polarization is accountable for the suppressed non-radiative recombination. This work provides an understanding of the excellent performance of metal halide perovskite solar cells.
低非辐射复合分数为金属卤化物钙钛矿太阳能电池奠定了基础。然而，金属卤化物钙钛矿材料中低非辐射复合的起源仍未得到很好的理解。在此，我们发现通过施加电场，孪晶四方相甲脒铅卤（MAPbICl）中的非辐射复合明显受到抑制，从而使开路电压从 1.12 V 显著增加到 1.26 V。通过控制实验排除了离子迁移和光浸泡对开路电压增强的可能影响。微观和宏观特性揭示了铁弹性晶格变形与非辐射复合抑制之间的优异相关性。计算结果表明，自稳定变形畴壁中存在晶格极化，表明晶格极化促进的电荷分离是抑制非辐射复合的原因。这项工作提供了对金属卤化物钙钛矿太阳能电池优异性能的理解。
