Abrupt p-n junction using ionic gating at zero-bias in bilayer graphene

Abstract Graphene is a promising candidate for optoelectronic applications. In this report, a double gated bilayer graphene FET has been made using a combination of electrostatic and electrolytic gating in order to form an abrupt p-n junction. The presence of two Dirac peaks in the gating curve of t...

Full description

Saved in:
Bibliographic Details
Main Authors: Sameer Grover, Anupama Joshi, Ashwin Tulapurkar, Mandar M. Deshmukh
Format: article
Language:EN
Published: Nature Portfolio 2017
Subjects:
R
Q
Online Access:https://doaj.org/article/bd14d70d4d3141309c43d73d68e9ef94
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:Abstract Graphene is a promising candidate for optoelectronic applications. In this report, a double gated bilayer graphene FET has been made using a combination of electrostatic and electrolytic gating in order to form an abrupt p-n junction. The presence of two Dirac peaks in the gating curve of the fabricated device confirms the formation of a p-n junction. At low temperatures, when the electrolyte is frozen intentionally, the photovoltage exhibits a six-fold pattern indicative of the hot electron induced photothermoelectric effect that has also been seen in graphene p-n junctions made using metallic gates. We have observed that the photovoltage increases with decreasing temperature indicating a dominant role of supercollision scattering. Our technique can also be extended to other 2D materials and to finer features that will lead to p-n junctions which span a large area, like a superlattice, that can generate a larger photoresponse. Our work creating abrupt p-n junctions is distinct from previous works that use a source–drain bias voltage with a single ionic gate creating a spatially graded p-n junction.