▎ 摘　　要

Unstable characteristics of graphene field effect transistors (FETs) have generated concerns about the feasibility of graphene electronic devices. Two dominant mechanisms of instability, charge trapping and interfacial redox reaction, and their quantitative contributions were investigated for chemical vapor deposited graphene by analyzing the transient responses of the hysteretic characteristics in microseconds to milliseconds range. In contrast to previous reports emphasizing the role of the interfacial redox reaction, we have found that charge trapping at the interface is responsible for 78-87% of the hysteresis and that the interfacial redox reaction at the graphene/SiO2 interface contributes only 13-22%. Systematic analysis on the temperature and ambient dependence of instability suggest that graphene FETs can operate more reliably with a proper passivation to create an oxygen deficient environment. (C) 2013 Elsevier Ltd. All rights reserved.