Relating Hysteresis and Electrochemistry in Graphene Field Effect Transistors

TL;DR

This paper investigates the origin of hysteresis in graphene FETs, linking electrochemical interactions and charge transfer mechanisms, especially related to environmental pH effects, to better understand device behavior.

Contribution

It provides a new interpretation connecting electrochemical effects with hysteresis in graphene FETs, emphasizing the role of charge trapping and environmental pH sensitivity.

Findings

Hysteresis in graphene FETs is linked to electrochemical charge trapping.

Environmental pH influences the hysteresis behavior.

Graphene's sensitivity to local pH affects its electronic properties.

Abstract

Hysteresis and commonly observed p-doping of graphene based field effect transistors (FET) was already discussed in reports over last few years. However, the interpretation of experimental works differs; and the mechanism behind the appearance of the hysteresis and the role of charge transfer between graphene and its environment are not clarified yet. We analyze the relation between electrochemical and electronic properties of graphene FET in moist environment extracted from the standard back gate dependence of the graphene resistance. We argue that graphene based FET on a regular SiO2 substrate exhibits behavior that corresponds to electrochemically induced hysteresis in ambient conditions, and can be caused by charge trapping mechanism associated with sensitivity of graphene to the local pH.