Simple method to synthesize larger n 2D perovskite from (C(NH2)3)(CH3NH3)n[PbnI3n+1] of n = 1 using isopropanol

Abstract

Two-dimensional (2D) perovskite of (C(NH 2 ) 3 )(CH 3 NH 3 ) n [Pb n I 3n+1 ] (shorten as (GA)MA n [Pb n I 3n+1 ]) is with alternating cations (GA + and MA + ) in the interlayer space (ACI). n = 1 of (GA)MAPbI 4 film can transform from red to black in appearance after soaking in isopropanol (IPA) for 5 s, resulting in the peaks of PL from 570 nm to 770 nm. Using X-ray diffraction and Fourier-transform infrared spectroscopy, we find that the IPA can dissolve GA + cation from the film effectively, thus n = 1 layered structure is destroyed, leaving larger n phases of (GA)MA n [Pb n I 3n+1 ] in film. By controlling the reaction time with IPA solvent, the n = 1 film can rearrange into new material of mixture with various n values, which present tunable absorption and photoluminescence spectra. Our work may not only explore the novel phenomena of ACI 2D perovskite, but also provide a simple method to synthesize quasi 2D perovskite with adjustable n values. • Isopropanol (IPA) can solve GA + effectively from (GA)MAPbI 4 film. • Large n phases of (GA)MA n [Pb n I 3n+1 ]) was left after IPA treatment. • Modifying the reaction time of (GA)MAPbI 4 film can achieve tunable n materials. • The novel phenomena of ACI 2D perovskite.