(Phys.org)—Optoelectronic devices that combine electronics and photonics are incorporating two-dimensional (2D) materials for a range of applications. At the same time,cooperative phenomena – in which a system's individual components appear to act as a single entity rather than independently – have yet to be widely investigated, an important example being ferroelectricity (spontaneous electric polarization that can be reversed by an electric field) in the 2D limit. Recently, and however,scientists at Nanyang Technological University, Singapore have demonstrated room-temperature out-of-plane ferroelectricity (that is, orthogonal to the 2D fabric) in 2D CuInP2S6 (copper indium thiophosphate) with a ~320 K transition temperature,as well as switchable polarization in 4 nm CuInP2S6 flakes. The researchers state that their findings create the opportunity of sensors, actuators, and non-volatile memory devices,various van der Waals heterostructures (devices made from layers of dissimilar 2D crystals in which forces are based on molecular attraction or repulsion rather than covalent or ionic bonds), and other novel applications based on 2D ferroelectricity.
Source: phys.org