Ferroelectric semiconductor junctions based on graphene/In<sub>2</sub>Se<sub>3</sub>/graphene van der Waals heterostructures
Shihong Xie, Anubhab Dey, Wenjing Yan, Z. R. Kudrynskyi, Nilanthy Balakrishnan, O. Makarovsky, Z. D. Kovalyuk, Eli G. Castanon, Oleg Kolosov, Kaiyou Wang, A. Patanè
Abstract
Abstract The miniaturization of ferroelectric devices offers prospects for non-volatile memories, low-power electrical switches and emerging technologies beyond existing Si-based integrated circuits. An emerging class of ferroelectrics is based on van der Waals (vdW) two-dimensional materials with potential for nano-ferroelectrics. Here, we report on ferroelectric semiconductor junctions (FSJs) in which the ferroelectric vdW semiconductor α -In 2 Se 3 is embedded between two single-layer graphene electrodes. In these two-terminal devices, the ferroelectric polarization of the nanometre-thick In 2 Se 3 layer modulates the transmission of electrons across the graphene/In 2 Se 3 interface, leading to memristive effects that are controlled by applied voltages and/or by light. The underlying mechanisms of conduction are examined over a range of temperatures and under light excitation revealing thermionic injection, tunnelling and trap-assisted transport. These findings are relevant to future developments of FSJs whose geometry is well suited to miniaturization and low-power electronics, offering opportunities to expand functionalities of ferroelectrics by design of the vdW heterostructure.