High in-plane piezoelectricity of two-dimensional Janus BiOX (X = Cl, Br, and I) monolayers

摘要

? 2022 Elsevier B.V.Piezoelectric materials can realize the direct conversion of strain and voltage, and have been widely used in the field of energy supply of micro-nano devices and pressure sensing. Based on the unique Janus structure, the electronic structures and piezoelectric properties of the BiOX (X = Cl, Br and I) monolayers were systematically studied by using first principles calculations. The results of the calculations show that the BiOI monolayer exhibits a largest in-plane piezoelectric coefficients (d11) value of 34.36 pm/V, which is far higher than the previously reported two-dimensional (2D) materials, such as MoS2 (3.73 pm/V) and BiXY (the largest BiSI is 23.11 pm/V), the sensitive and regular response of the BiOI model also broaden its application opportunities in micro-nano piezoelectric devices.