Flexoelectric effects in a bent α-In2Se3 ferroelectric monolayer

Flexoelectric effects in materials can bring novel physical properties that are absent in their perfect crystal, and have a wide range of applications, such as mechanical sensors and wrinkled triboelectric nanogenerators. In this work, electronic structures and transport properties of bended α-In2Se3 monolayer are investigated through first-principles calculations and nonequilibrium Green's function (NEGF). We find that two different kinds of type-II band structures can be obtained in P↑ and P↓ flexed α-In2Se3, which show opposite band bending. Carriers in the center of P↑ and P↓ flexed α-In2Se3 are mainly holes and electrons, respectively, which dominate the current behavior of the α-In2Se3 p-i-n (PIN) field-effect transistor (FET). The P↑ PIN-FET has enhanced forward current and the rectification ratio due to the larger density of holes. Our study achieves the homogeneous junction through bended α-In2Se3, which may simplify the device procession and be used as electromechanical sensors.