Operando photoelectron spectroscopy analysis of graphene field-effect transistors

Abstract

In this study, operando photoelectron spectroscopy was used to characterize the performance of graphene field-effect transistors under working conditions. By sweeping the back-gate voltages, the carrier concentration of the graphene channel on the 150 nm Si3N4/Si substrate was tuned. From the C1s core level spectra acquired under the application of different gate voltages, the binding energy shifts caused by electric-field effects were obtained and analyzed. Together with the C1s peak shape information and the photoluminescence spectrum of the Si3N4/Si substrate, the presence of local potential across the X-ray beam spot associated with defects and gate leakage current in amorphous Si3N4 was identified. The presence of defects in Si3N4/Si substrate could not only screen the partial electric field generated by the back gate but also serve as long-range scattering centers to the carriers, thus affecting charge transport in the graphene channel. Our findings will help further investigate the dielectric/graphene interface properties and accelerate the utilization of graphene in real device applications.

Editorial for focus on manipulations of atomic and molecular layers and its applications in energy, environment sciences and optoelectronic devices

“…The last but not the least, there has a study characterizing the performance of graphene FETs using an operando XPS under working conditions [22]. In the study, Lu et al could identified the presence of local potential across the x-ray beam spot associated with defects and gate leakage current.…”