High-Yield Production and Transfer of Graphene Flakes Obtained by Anodic Bonding

Abstract

We report large-yield production of graphene flakes on glass by anodic bonding. Under optimum conditions, we counted several tens of flakes with lateral size around 20-30 μm and a few tens of flakes with larger size. About 60-70% of the flakes have a negligible D peak. We show that it is possible to easily transfer the flakes by the wedging technique. The transfer on silicon does not damage graphene and lowers the doping. The charge mobility of the transferred flakes on silicon is on the order of 6000 cm(2)/V s (at a carrier concentration of 10(12) cm(-2)), which is typical for devices prepared on this substrate with exfoliated graphene.

Spectroscopic investigation of defects in two-dimensional materials

“…[64]. In contrast, defective graphene samples produced by ion bombardment and anodic bonding [99], which mainly contain vacancy-like defects, show a smaller I D /I D′ (7), while polycrystalline graphite, where defects are commonly GBs, shows an even smaller I D /I D′ (3.5) [64]. The above results demonstrate that Raman spectroscopy, i.e.…”

Production and processing of graphene and 2d crystals

“…Anodic bonding is widely used in the microelectronics industry to bond Si wafers to glass 47 , to protect them from humidity or contaminations 48 . When employing this technique to produce SLGs 49,50 , graphite is first pressed onto a glass substrate, and a high voltage of few KVs (0.5-2 kV) is applied between the graphite and a metal back contact (see Fig.1b), and the glass substrate is then heated (∼200 • C for∼10-20mins) 49,50 . If a positive voltage is applied to the top contact, a negative charge accumulates in the glass side facing the positive electrode, causing the decomposition of Na 2 O impurities in the glass into Na + and O − 2 ions 49,50 .…”

Probing the Nature of Defects in Graphene by Raman Spectroscopy

“…33 Micro Raman measurements were performed with a confocal Witec spectrometer equipped with a 514.5nm (2.41eV) laser in backscattering configuration. We used a 100x objective giving a laser spot size of about 400nm.…”