Modeling Radiation-Induced Scattering in Graphene

In this paper we analyze and model conductivity ( σ) and mobility ( μ) degradation in graphene due to total ionizing dose (TID)-induced carrier scattering effects. The analysis technique presented in this paper utilizes in situ measurements of low-field transport in graphene samples irradiated with gamma rays (Co-60) in multiple doses up to 2 Mrad(Si). The carrier backscattering mean free path ( λ) is extracted as a function of ionizing radiation by fitting the measurements with analytical calculations of conductivity in graphene derived from scattering theory. This derivation is based on the Landauer approach and incorporates the linear dispersion relation near the Dirac point, and the two-dimensional (2-D) structure of graphene. The extractions of λ are used to model the impact of radiation-induced scattering on the conductance ( G) of graphene FETs as a function of channel length ( L) from the diffusive (i.e., for L ≫ λ) to the ballistic limit (i.e., for L ≪ λ).