Rosales Bryan A, Mundt Laura E, Allen Taylor G, Moore David T, Prince Kevin J, Wolden Colin A, Rumbles Garry, Schelhas Laura T, Wheeler Lance M
Center for Chemistry and Nanoscience, National Renewable Energy Laboratory, 15013 Denver West Parkway, Golden, CO, 80401, USA.
SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, CA, 94025, USA.
Nat Commun. 2020 Oct 16;11(1):5234. doi: 10.1038/s41467-020-19009-z.
Metal halide perovskites feature crystalline-like electronic band structures and liquid-like physical properties. The crystal-liquid duality enables optoelectronic devices with unprecedented performance and a unique opportunity to chemically manipulate the structure with low energy input. In this work, we leverage the low formation energy of metal halide perovskites to demonstrate multicolor reversible chromism. We synthesized layered Ruddlesden-Popper FAPbX (FA = formamidinium, X = I, Br; n = number of layers = 1, 2, 3 … ∞) and reversibly tune the dimensionality (n) by modulating the strength and number of H-bonds in the system. H-bonding was controlled by exposure to solvent vapor (solvatochromism) or temperature change (thermochromism), which shuttles FAX salt pairs between the FAPbX domains and adjacent FAX "reservoir" domains. Unlike traditional chromic materials that only offer a single-color transition, FAPbX films reversibly switch between multiple colors including yellow, orange, red, brown, and white/colorless. Each colored phase exhibits distinct optoelectronic properties characteristic of 2D superlattice materials with tunable quantum well thickness.
金属卤化物钙钛矿具有类似晶体的电子能带结构和类似液体的物理性质。这种晶体 - 液体二元性使得光电器件具有前所未有的性能，并且提供了一个以低能量输入对结构进行化学操纵的独特机会。在这项工作中，我们利用金属卤化物钙钛矿的低形成能来展示多色可逆变色现象。我们合成了层状的Ruddlesden - Popper型FAPbX（FA = 甲脒，X = I、Br；n = 层数 = 1、2、3 … ∞），并通过调节体系中氢键的强度和数量来可逆地调整维度（n）。通过暴露于溶剂蒸汽（溶剂致变色）或温度变化（热致变色）来控制氢键，这使得FAX盐对在FAPbX域和相邻的FAX“储库”域之间穿梭。与仅提供单一颜色转变的传统变色材料不同，FAPbX薄膜可在多种颜色之间可逆切换，包括黄色、橙色、红色、棕色和白色/无色。每个有色相都表现出具有可调量子阱厚度的二维超晶格材料特有的独特光电性质。
