Electronic devices based on two-dimensional semiconductors suffer from limited electrical stability because charge carriers originating from the semiconductors interact with defects in the surrounding insulators. In field-effect transistors, the resulting trapped charges can lead to large hysteresis and device drifts, particularly when common amorphous gate oxides (such as silicon or hafnium dioxide) are used, hindering stable circuit operation. Here, we show that device stability in graphene-based field-effect transistors with amorphous gate oxides can be improved by Fermi-level tuning. We deliberately tune the Fermi level of the channel to maximize the energy distance between the charge carriers in the channel and the defect bands in the amorphous aluminium gate oxide. Charge trapping is highly sensitive to the energetic alignment of the Fermi level of the channel with the defect band in the insulator, and thus, our approach minimizes the amount of electrically active border traps without the need to reduce the total number of traps in the insulator.

基于二维半导体的电子设备的电稳定性有限，因为源自半导体的电荷载流子与周围绝缘体中的缺陷相互作用。在场效应晶体管中，由此产生的俘获电荷会导致较大的滞后和器件漂移，尤其是在使用常见的非晶栅极氧化物（如硅或二氧化铪）时，会阻碍电路的稳定运行。在这里，我们展示了具有非晶栅氧化物的基于石墨烯的场效应晶体管中的器件稳定性可以通过费米能级调谐来提高。我们特意调整了通道的费米能级，以使通道中的电荷载流子与非晶铝栅氧化物中的缺陷带之间的能量距离最大化。