Tuning the luminescent properties of a three-dimensional perovskite ferroelectric (Me-Hdabco)CsI3via Sn(ii) doping

Abstract

As promising functional materials, organic–inorganic hybrid metal halide perovskites have attracted significant interest because of their excellent photovoltaic performance. However, although considerable efforts have been made, three-dimensional (3D) metal halide perovskites beyond lead halides have been rarely reported. Herein, a new 3D organic–inorganic hybrid ferroelectric material (Me-Hdabco)CsI₃ (1, Me-Hdabco = N-methyl-1,4-diazoniabicyclo[2.2.2]octane) was synthesized and characterized. 1 underwent a ferroelectric to paraelectric phase transition at T_c = 441 K, which was investigated by differential scanning calorimetry (DSC), dielectric measurements, and variable temperature structural analyses. Moreover, 1 shows a clear ferroelectric domain switching recorded by piezoelectric force microscopy. More interestingly, the pristine colorless crystal of 1 has no photoluminescence properties, while 10% Sn(II):(Me-Hdabco)CsI₃ shows intense photoluminescence with a quantum yield of 8.90% under UV excitation. This finding will open up a new avenue to probe organic–inorganic hybrid multifunctional materials integrated ferroelectric and photoluminescence.