Interlayer cation engineering to regulate the photoelectric properties of lead bromide Dion–Jacobson hybrid perovskites

Abstract

Dion–Jacobson (DJ) phase hybrid perovskites (HPs) have achieved impressive performance and high stability in optoelectronics devices. Despite that, research on the relationship between the structure and photoelectric properties of DJ HPs is still rare; particularly, the effect of diammonium cations with different conformations between the interlayers on the structure–activity relationship has not been reported. Herein, three kinds of DJ HP bulk crystals, BDAPbBr₄ (1), 2AMPPbBr₄ (2) and 2AMPYPbBr₄ (3), have been constructed by interlayer cation engineering with the linear diammonium 1,4-butanediammonium (BDA), cyclic aliphatic diammonium 2-(aminomethyl)piperidinium (2AMP) and aromatic diammonium 2-(aminomethyl)pyridinium (2AMPY), respectively. These DJ HPs based on diammonium cations with different conformations exhibit diverse structures and optical and electronic properties. After an in-depth analysis, the photoelectric properties of these DJ HPs have been found to be significantly affected by the interlayer spacing, the insertion depth of the diammonium cations into the inorganic skeleton and the distortion degree of the inorganic layer. Finally, compound 3 constructed using the aromatic diammonium has been found to possess the shortest interlayer spacing (3.404 Å), the deepest insertion (1.147 Å) and the smallest distortion (173.7°), which afford it better photodetection performance (3.2 × 10¹¹ Jones) than 1 (3.8 × 10¹⁰ Jones) and 2 (1.8 × 10¹¹ Jones) under 405 nm irradiation. More importantly, it is precisely because of the rigidity and aromaticity of the 2AMPY cations that compound 3 has the best optical and photoelectric performance. These findings provide a foundation for designing optoelectronic devices with distinguished performance in the future.