The development of high-performance radiation detectors is essential for commercial, scientific, and securityapplications [1]. Due to the unique electronic properties of graphene (high-speed, low-noise), recent radiationdetectors utilize graphene field effect transistors to sense charge carriers produced by radiation interactions in agated semiconductor [2]. A study of the energy de...

The high-frequency performance of top-gated graphene field-effect transistors (GFETs) depends to a large extent on the saturation velocity charge carriers, limited by inelastic scattering surface optical phonons from dielectrics surrounding channel. In this work, we show that, simply changing channel dielectric with material having higher phonon energy, one could improve transit frequency and m...