Non‐Volatile Reconfigurable p–n Junction Utilizing In‐Plane Ferroelectricity in 2D WSe2/α‐In2Se3 Asymmetric Heterostructures

Abstract It is impossible to imagine modern electronic circuitry without a p–n junction—an essential building block for transistors, rectifiers, amplifiers, photovoltaics, etc. Conventional fabrication processes (ion implantation or chemical diffusion) result in an immutable potential configuration depriving reconfigurability. In contrast, the superior electrostatic tunability, dangling bonds‐ and reconstruction‐free interfaces are some of the key features of 2D based heterostructures, making them promising candidates for cutting‐edge optoelectronic and memory applications. Herein, the intercoupled 2D ferroelectricity of 𝛼‐In 2 Se 3 is utilized to introduce micron‐scale, non‐volatile electrostatic doping in ambipolar WSe 2 , enabling reconfigurable p–n junction. The actuation mechanism is based on the strong polarization field along the edge topology of In 2 Se 3 . The fabricated device presents stable p–n to n–p switching, a superior rectification ratio of ≈10 6 , and a low leakage current of ≈10 −12 A. Furthermore, the switchable short‐circuit current response is utilized to demonstrate a novel self‐powered, non‐volatile memory based on photovoltaic reading. The ferroelectric non‐volatility coupled with the ability to control the device operation using optical and electrical signals paves the way for ultrathin energy‐efficient, multi‐level optoelectronic and in‐memory logic devices.