Polycrystalline Methylammonium–Lead Bromide Perovskite Films for Photonic Metasurfaces.

Polycrystalline films of organic–inorganic perovskite semiconductors are promising as a base for designing functional optical metasurfaces. The requirements to their structural quality, thickness uniformity, homogeneity, and absence of defects are much more stringent than those for perovskite films used in photovoltaics. The results of searching for the optimal conditions of one-stage synthesis of methylammonium-lead bromide films by spin coating are reported, and successful preparation of subwavelength optical gratings based on them using focused ion beam (FIB) processing is described. The measured light transmission spectra demonstrated excellent optical quality of the gratings and confirmed the possibility of forming semiconductor photonic metasurfaces with submicron periodicity and high-Q dielectric resonances. [ABSTRACT FROM AUTHOR]