Reversible Photochromism in ⟨110⟩ Oriented Layered Halide Perovskite

• Published in: ACS nano Vol. 16; no. 2; pp. 2942 - 2952
• Main Authors: Kanwat, Anil, Ghosh, Biplab, Ng, Si En, Rana, Prem J. S, 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 G, Mathews, Nripan
• Format: Journal Article
• Language: English
• Published: United States American Chemical Society 22.02.2022
• Subjects: self-adaptation; sensors; halide perovskites; 110⟩ perovskite; photochromism
• ISSN: 1936-0851; 1936-086X
• DOI: 10.1021/acsnano.1c10098

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 FA n+2Pb n Br3n+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 FA n+2Pb n Br3n+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 FA n+2Pb n Br3n+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.