Influence of the Organic Chain on the Optical Properties of Two-Dimensional Organic–Inorganic Hybrid Lead Iodide Perovskites

Two-dimensional (2D) organic–inorganic hybrid perovskites (OIHPs) have recently drawn great interest due to their easy synthesis and excellent photoelectric properties. With tunable bandgaps, 2D OIHPs have been widely investigated for use in optoelectronic sensors, photodetectors, and solar cells. In this work, we synthesized three types of 2D perovskites with different organic chains, (CH3(CH2)3NH3)2PbI4 (C4, (BA)2PbI4), (CH3(CH2)5NH3)2PbI4 (C6, (HA)2PbI4), and (CH3(CH2)7NH3)2PbI4 (C8, (OA)2PbI4), and investigated their photoelectric properties. With increasing organic chain length, the interlayer spacing, bandgaps, and stability in air increased correspondingly. In addition, tunable optoelectronic properties were achieved when these three perovskites with different organic chain cations were employed to fabricate photodetectors. The results provide an effective method for synthesizing various OIHPs via tuning different organic cations and are helpful to broaden the applications of OIHPs in photoelectric devices.