Self-Powered Photodetector Using Two-Dimensional Ferroelectric Dion–Jacobson Hybrid Perovskites
In‐Hyeok Park, Ki Chang Kwon, Ziyu Zhu, Xiao Wu, Runlai Li, Qing‐Hua Xu, Kian Ping Loh
Abstract
Dion–Jacobson (DJ) phase organic–inorganic hybrid perovskites (OIHPs) have emerged as promising alternatives to Ruddlesden–Poppers perovskites because of their chemical stability and ferroelectric phase. Here we fabricate a ferroelectricity-modulated photodetector based on the n = 2 homologue of the ferroelectric two-dimensional DJ-OIHP (AMP)(MA)Pb2I7 (DJPn=2, AMP = 4-(aminomethyl)piperidinium; MA = methylammonium), which shows an out-of-plane polarization and a saturated polarization (Ps) value of 3.7 μC/cm2. The coercive field of DJPn=2 (0.34 kV/cm) is lower than that for the n = 1 homologue (AMP)PbI4 (DJPn=1,0.4 kV/cm). DJPn=2 has a much longer carrier lifetime and absorption edge (580 nm, 2.13 eV) in comparison to DJPn=1 (523 nm, 2.37 eV); thus, DJPn=2 can be used for efficient photodetection in the visible range, in which a responsivity of 0.16 mA/W was achieved at 532 nm. The influence of remnant polarization on the direction and magnitude of the photocurrent was also demonstrated.