X-ray induced electrostatic graphene doping via defect charging in gate dielectric

Abstract Graphene field effect transistors are becoming an integral part of advanced devices. Hence, the advanced strategies for both characterization and tuning of graphene properties are required. Here we show that the X-ray irradiation at the zero applied gate voltage causes very strong negative...

Full description

Bibliographic Details
Main Authors: Pavel Procházka, David Mareček, Zuzana Lišková, Jan Čechal, Tomáš Šikola
Format: Article
Language:English
Published: Nature Publishing Group 2017-04-01
Series:Scientific Reports
Online Access:https://doi.org/10.1038/s41598-017-00673-z
Description
Summary:Abstract Graphene field effect transistors are becoming an integral part of advanced devices. Hence, the advanced strategies for both characterization and tuning of graphene properties are required. Here we show that the X-ray irradiation at the zero applied gate voltage causes very strong negative doping of graphene, which is explained by X-ray radiation induced charging of defects in the gate dielectric. The induced charge can be neutralized and compensated if the graphene device is irradiated by X-rays at a negative gate voltage. Here the charge neutrality point shifts back to zero voltage. The observed phenomenon has strong implications for interpretation of X-ray based measurements of graphene devices as it renders them to significantly altered state. Our results also form a basis for remote X-ray tuning of graphene transport properties and X-ray sensors comprising the graphene/oxide interface as an active layer.
ISSN:2045-2322