專題演講

2018/09/25(Tue)     10:30 -12:00    5th Floor(1st meeting room)

Title

Two-dimensional ferroelectric tunnel junction

Speaker

Prof. Chun-Gang Duan

Key Laboratory of Polar Materials and Devices, Ministry of Education, East China Normal University

Abstract

Ferroelectric tunnel junctions (FTJs) have triggered considerable attention in the advanced applications of non-volatile information devices. However, critical thickness for ferroelectricity limits FTJs towards their application at the nanoscale. Recently, ferroelectricity is demonstrated to intrinsically exist in some two-dimensional (2D) materials. Here, through the opposite dopant on the two sides of the monolayer group-IV monochalcogenides (GIVMs), we design a novel 2D-FTJ employing p-type semiconductor/ferroelectric/n-type semiconductor homostructure, coupling the electron tunneling with the in-plane ferroelectricity. This structure makes it possible to dynamically modulate tunneling barrier height as well as the width in response to the ferroelectric polarization reversal, and promises to realize a significantly enhanced tunneling electroresistance (TER) effect. Combining first-principles calculations with non-equilibrium Green’s function formalism, herein, we reveal this mechanism by using In:SnSe/SnSe/Sb:SnSe homostructure as a prototypical example, where a large TER effect of around 1.46×103 % is obtained. Compared with the normal vertical FTJs, this lateral 2D-FTJ enormously improves the TER effect and show exciting prospects for device application with higher data integration and reliable information retention in the future.