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

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
Práce se zabývá elektrostatickým dotováním grafenu prostřednictvím nabíjení defektů v hradlovém dielektriku vyvolaného rentgenovým zářením.

Keywords

Grafen, tranzistor GFET, rentgeové záření, nabité defekty, hradlové dielektrikum, Graphene, Field effect transistor, X-rays, Charged defects, Gate dielectrics

Citation

Scientific Reports. 2017, vol. 7, issue 1, p. 1-7.
https://www.nature.com/articles/s41598-017-00673-z

Document type

Peer-reviewed

Document version

Published version

Language of document

en

Document licence

Creative Commons Attribution 4.0 International
http://creativecommons.org/licenses/by/4.0/