2D Organic-Inorganic Perovskite (ATHP)2PbI4 With Huge Out-of-Plane Piezoelectric Properties

Recently, organic-inorganic hybrid perovskite has attracted increasingly attention because of its excellent piezoelectric and ferroelectric properties.In this letter, the first principles method was employed to analyze the piezoelectric properties of two-dimensional (2D) organic-inorganic perovskite (4-aminotetrahydropyran, ATHP) 2 PbX 4 (X = Cl, Br and I).The calculation shows that 2D (ATHP) 2 PbX 4 has large out-of-plane dipole moment and excellent out-of-plane piezoelectric properties.Among them, the out-of-plane piezoelectric coefficient d 31 of 2D (ATHP) 2 PbI 4 reaches 41.90 pm/V, which is about 8 times the out-of-plane piezoelectric coefficient d 33 of bulk material AlN, and one to two orders of magnitude larger than d 31 of most 2D piezoelectric materials.The electronic properties of 2D (ATHP) 2 PbX 4 are calculated to reveal its energy band structure and charge density.The elastic tensors of 2D (ATHP) 2 PbX 4 is calculated.The stress-strain analysis suggested the 2D (ATHP) 2 PbX 4 has an ultra-soft mechanical flexibility.Our research shows that 2D (ATHP) 2 PbX 4 is of great application value in various micro-nano piezoelectric devices.