Manipulation of the Structure and Optoelectronic Properties through Bromine Inclusion in a Layered Lead Bromide Perovskite

作者：Lin-Jie Yang, Wenye Xuan, David Webster, Lethy Krishnan Jagadamma, Teng Li, David Miller, David B. Cordes, Alexandra M. Z. Slawin, Graham A. Turnbull, Ifor D. W. Samuel, Hsin‐Yi Tiffany Chen, Philip Lightfoot, Matthew S. Dyer, Julia L. Payne · 发表于：Chemistry of Materials · 年份：2023 · DOI：10.1021/acs.chemmater.2c03125 · 被引用次数：10 · 研究领域：Perovskite Materials and Applications、Solid-state spectroscopy and crystallography、2D Materials and Applications

High Resolution Image Download MS PowerPoint Slide One of the great advantages of organic–inorganic metal halides is that their structures and properties are highly tuneable and this is important when optimizing materials for photovoltaics or other optoelectronic devices. One of the most common and effective ways of tuning the electronic structure is through anion substitution. Here, we report the inclusion of bromine into the layered perovskite [H 3 N(CH 2 ) 6 NH 3 ]PbBr 4 to form [H 3 N(CH 2 ) 6 NH 3 ]PbBr 4 ·Br 2, which contains molecular bromine (Br 2 ) intercalated between the layers of corner-sharing PbBr 6 octahedra. Bromine intercalation in [H 3 N(CH 2 ) 6 NH 3 ]PbBr 4 ·Br 2 results in a decrease in the band gap of 0.85 eV and induces a structural transition from a Ruddlesden–Popper-like to Dion–Jacobson-like phase, while also changing the conformation of the amine. Electronic structure calculations show that Br 2 intercalation is accompanied by the formation of a new band in the electronic structure and a significant decrease in the effective masses of around two orders of magnitude. This is backed up by our resistivity measurements that show that [H 3 N(CH 2 ) 6 NH 3 ]PbBr 4 ·Br 2 has a resistivity value of one order of magnitude lower than [H 3 N(CH 2 ) 6 NH 3 ]PbBr 4, suggesting that bromine inclusion significantly increases the mobility and/or carrier concentration in the material. This work highlights the possibility of using molecular inclusion as an alternativ...