Single Gate P-N Junctions in Graphene-Ferroelectric Devices

TL;DR

This paper demonstrates a method to create and control graphene p-n junctions using a ferroelectric substrate and environmental doping, enabling on-demand switching with a single gate.

Contribution

It introduces a simple fabrication technique for graphene p-n junctions with ferroelectric substrates and demonstrates their controllable, hysteresis-based switching behavior.

Findings

P-n junctions can be formed via substrate modifications and environmental doping.

The ferroelectric substrate induces hysteresis in doping levels.

A single backgate can control the activation and deactivation of the p-n junctions.

Abstract

Graphene's linear dispersion relation and the attendant implications for bipolar electronics applications have motivated a range of experimental efforts aimed at producing p-n junctions in graphene. Here we report electrical transport measurements of graphene p-n junctions formed via simple modifications to a PbZr$_{0.2}$Ti$_{0.8}$O$_3$ substrate, combined with a self-assembled layer of ambient environmental dopants. We show that the substrate configuration controls the local doping region, and that the p-n junction behavior can be controlled with a single gate. Finally, we show that the ferroelectric substrate induces a hysteresis in the environmental doping which can be utilized to activate and deactivate the doping, yielding an `on-demand' p-n junction in graphene controlled by a single, universal backgate.