Graphene electrical properties modulated by swift heavy ion irradiation

Abstract

Changes in electrical properties of graphene devices induced by the energetic ion irradiation are very important for their application in harsh radiation environment. This paper presents the modulating behavior of electrical properties of graphene-based devices induced by swift heavy ions (SHIs). Graphene field effect transistors (GFETs) were irradiated by 1.79 GeV Ta ions and it was found that at lower fluence (109-1010 ions/cm2), the SHIs irradiation can effectively optimize the performance of GFETs, while at higher fluence (∼1011 ions/cm2), the electrical properties of the devices were significantly deteriorated after the irradiation process. The effective length and width of the graphene strip and irradiation fluence are the main factors that determine the improvement in performance of GFETs. Raman spectroscopy was employed to figure out the correlation between the initial defect density in graphene and changes in electrical performance of GFETs. It was shown that the competition among various factors such as the doping, local annealing and defect creation dominates the GFET performance. This work explores the best conditions for improving the electrical properties of GFETs and provides an important reference data for the utilization of graphene based irradiated devices in aerospace electronics.