Reversible photochromism in ⟨110⟩ oriented layered halide perovskite

• Main Authors: Kanwat, Anil, Ghosh, Biplab, Ng, Si En, Rana, Prem Jyoti Singh, Lekina, Yulia, Hooper, Thomas J. N., Yantara, Natalia, Kovalev, Mikhail, Chaudhary, Bhumika, Kajal, Priyanka, Febriansyah, Benny, Tan, Qi Ying, Klein, Maciej, Shen, Ze Xiang, Ager, Joel W., Mhaisalkar, Subodh Gautam, Mathews, Nripan
• Other Authors: School of Materials Science and Engineering
• Format: Article
• Language: English
• Published: 2022
• Subjects: Engineering::Materials::Energy materials; Halide Perovskites; Photochromism
• Online Access: https://hdl.handle.net/10356/154975
• Institution: Nanyang Technological University

Extending halide perovskites' optoelectronic properties to stimuli-responsive chromism enables switchable optoelectronics, information display, and smart window applications. Here, we demonstrate a band gap tunability (chromism) via crystal structure transformation from three-dimensional FAPbBr3 to a ⟨110⟩ oriented FAn+2PbnBr3n+2 structure using a mono-halide/cation composition (FA/Pb) tuning. Furthermore, we illustrate reversible photochromism in halide perovskite by modulating the intermediate n phase in the FAn+2PbnBr3n+2 structure, enabling greater control of the optical band gap and luminescence of a ⟨110⟩ oriented mono-halide/cation perovskite. Proton transfer reaction-mass spectroscopy carried out to precisely quantify the decomposition product reveals that the organic solvent in the film is a key contributor to the structural transformation and, therefore, the chromism in the ⟨110⟩ structure. These intermediate n phases (2 ≤ n ≤ ∞) stabilize in metastable states in the FAn+2PbnBr3n+2 system, which is accessible via strain or optical or thermal input. The structure reversibility in the ⟨110⟩ perovskite allowed us to demonstrate a class of photochromic sensors capable of self-adaptation to lighting.