The use of a Ga⁺focused ion beam to modify graphene for device applications

Abstract

In this work, we clarify the features of the lateral damage of line defects in single layer graphene. The line defects were produced through well-controlled etching of graphene using a Ga(+) focused ion beam. The lateral damage length was obtained from both the integrated intensity of the disorder induced Raman D band and the minimum ion fluence. Also, the line defects were characterized by polarized Raman spectroscopy. It was found that graphene is resilient under the etching conditions since the intensity of the defect induced Raman D peak exhibits a dependence on the direction of the lines relative to the crystalline lattice and also on the direction of the laser polarization relative to the lines. In addition, electrical measurements of the modified graphene were performed. Different ion fluences were used in order to obtain a completely insulating defect line in graphene, which was determined experimentally by means of charge injection and electric force microscopy measurements. These studies demonstrate that a Ga+ ion column combined with Raman spectroscopy is a powerful technique to produce and understand well-defined periodic arrays of defects in graphene, opening possibilities for better control of nanocarbon devices.

Ion‐Induced Defects in Graphite: A Combined Kelvin Probe and Raman Microscopy Investigation

“…The D/G intensity ratio changes correlate positively with changes in irradiation fluence. This trend is noted in several works, and is in agreement with the results from Lucchese et al that show the D/G ratio changes as the sp 2 domain size decreases, and also with results reported for ion‐irradiated graphene . Without direct comparison of the individual system state before and after irradiation contributions from other defect states in graphite cannot entirely be ruled out, however, our results strongly indicate D/G ratios are dependent on system defects due to irradiation.…”

Highly Enhanced Curie Temperature in Ga‐Implanted Fe3GeTe2 van der Waals Material

“…In addition to the sputtering effect, high energy Ga + irradiation has been reported to also result in amorphization or structural change of 2D materials. [ 15,16,17 ] A recent experiment [ 15 ] shows that a Ga dose of 3.1 × 10 15 ions cm −2 , which is similar to our case of 10 s exposure time (Ga dose 3.9 × 10 15 ions cm −2 ), to a single layer graphene could amorphize or change ≈1/3 layer into other structures. To search for any structural change of the Fe 3 GeTe 2 crystal due to Ga irradiation, we performed microdiffraction measurement.…”

Surface modification of multilayer graphene using Ga ion irradiation

“…The electrical behavior of monolayer graphene is affected by a completely insulating defect line obtained by Ga ion irradiation (30 keV). 11 The Hall mobility of monolayer graphene decreases when exposed to carbon ion irradiation (35 keV). This is thought to be caused by structural changes induced by defects from the irradiation.…”