Field effect transistors and photodetectors based on nanocrystalline graphene derived from electron beam induced carbonaceous patterns

Abstract

We describe a transfer-free method for the fabrication of nanocrystalline graphene (nc-graphene) on SiO₂ substrates directly from patterned carbonaceous deposits. The deposits were produced from the residual hydrocarbons present in the vacuum chamber without any external source by using an electron beam induced carbonaceous deposition (EBICD) process. Thermal treatment under vacuum conditions in the presence of Ni catalyst transformed the EBIC deposit into nc-graphene patterns, confirmed using Raman and TEM analysis. The nc-graphene patterns have been employed as an active p-type channel material in a field effect transistor (FET) which showed a hole mobility of ∼90 cm² V^-1 s^-1. The nc-graphene also proved to be suitable material for IR detection.