Photoluminescent Properties of Two-Dimensional Manganese(II)-Based Perovskites with Different-Length Arylamine Cations
Shihui He, Shiqiang Hao, Jiawei Lin, Na Wang, Jindong Cao, Zhongnan Guo, Christopher Wolverton, Jing Zhao, Quanlin Liu
Abstract
The participation of organic cations plays an important role in tuning broad-spectra emissions. Herein, we synthesized a series of Mn(II)-based two-dimensional (2D) halide perovskites with arylamine cations of different lengths having the general formula (C 6 H 5 (CH 2 ) x NH 3 ) 2 MnCl 4 ( x = 1–4), with the x = 4 compound reported here for the first time. With the increase in the −(CH 2 )– in organic cations, the distance between adjacent inorganic layers increases, causing the title compounds to exhibit different structural distortions. As the Mn–Cl–Mn angular distortion increases, the experimental optical band gaps of the title compounds increase correspondingly. When the angle distortion between the octahedrons of the compounds is similar, the band gaps may also be affected by the distortion of the octahedron itself (the bond-length distortion of 2 is greater than that of 4 ). Under UV-light irradiation at 298 K, all of the compounds exhibit two emission peaks centered at 480–505 and 610 nm, corresponding to the organic-cation emission and the 4 T 1 (G) to 6 A 1 (S) radiative transition of Mn 2+ ions, respectively. Among these title compounds, (PPA) 2 MnCl 4 [(PPA) + = C 6 H 5 (CH 2 ) 3 NH 3 + ] exhibits the strongest photoluminescence (PL). The study of the title compounds contributes to an in-depth understanding of the relationship between the structural distortion and optical properties of 2D Mn(II)-based perovskite materials.