韩国成均馆大学Nam-Gyu Park团队揭示了稳定钙钛矿太阳能电池的晶面依赖性降解和晶面工程。相关研究成果于2023年1月13日发表在《科学》。

大量的研究和策略已经致力于提高钙钛矿膜的稳定性；然而，不同钙钛矿晶面在稳定性中的作用仍然未知。

该文中，研究人员揭示了碘化甲脒铅（FAPbI₃）膜的面依赖性降解的潜在机制。研究表明，（100）面比（111）面更容易受到水分引起的降解。结合实验和理论研究，揭示了降解机理；观察到铅-碘（Pb-I）键距延长后的强水粘附，这导致（100）面上的δ-相变。通过工程设计，可以获得更高的（111）面表面分数，并且（111）为主的晶体FAPbI₃膜显示出优异的抗湿气稳定性。研究发现阐明了未知的晶面依赖性降解机制和动力学。

附：英文原文

Title: Unveiling facet-dependent degradation and facet engineering for stable perovskite solar cells

Author: Chunqing Ma, Felix T. Eickemeyer, Sun-Ho Lee, Dong-Ho Kang, Seok Joon Kwon, Michael Grtzel, Nam-Gyu Park

Issue&Volume: 2023-01-13

Abstract: A myriad of studies and strategies have already been devoted to improving the stability of perovskite films; however, the role of the different perovskite crystal facets in stability is still unknown. Here, we reveal the underlying mechanisms of facet-dependent degradation of formamidinium lead iodide (FAPbI3) films. We show that the (100) facet is substantially more vulnerable to moisture-induced degradation than the (111) facet. With combined experimental and theoretical studies, the degradation mechanisms are revealed; a strong water adhesion following an elongated lead-iodine (Pb-I) bond distance is observed, which leads to a δ-phase transition on the (100) facet. Through engineering, a higher surface fraction of the (111) facet can be achieved, and the (111)-dominated crystalline FAPbI3 films show exceptional stability against moisture. Our findings elucidate unknown facet-dependent degradation mechanisms and kinetics.

DOI: adf3349

Source: https://www.science.org/doi/10.1126/science.adf3349