Influence of defect density on the gas sensing properties of multi-layered graphene grown by chemical vapor deposition

Multilayer CVD graphene electrodes using a transfer-free process for the next generation of optically transparent and MRI-compatible neural interfaces

“…The ratio between the intensities of the D and the G peaks (I D /I G = 0.38) indicates the defects in the graphene layer, which in this case indicates a low number of defects after Mo removal. This ratio matches with the reported values for graphene on Mo for gas sensing applications 46 . The ratio between the intensities of the 2D and the G peaks (I 2 D /I G = 0.74) confirms the presence of multilayer graphene as the ratio is less than 1 40 .…”

Optimization of multilayer graphene-based gas sensors by ultraviolet photoactivation

“…Under exposure to NO 2 , devices displayed a decrease in resistance, indicating a p-type behaviour of the MLG, as also observed elsewhere [20,22,41,45,46]. Essentially, when the material is exposed to an oxidizing or electron acceptor molecule, such as NO 2 , electronic transfer increases the number of positive charge carriers, i.e., holes, leading to a decrease in the material resistance.…”

“…The results have shown that both MLG-based devices suffered a change in their conductivity under gas exposure, mainly caused by a charge transfer mechanism between the gaseous molecules and the graphene's surface [20,22,41,46]. In particular, the devices exhibited a p-type behaviour, as demonstrated by exposing the devices to an oxidizing analyte (NO 2 ) and two reducing analytes (CO and NH 3 ).…”

Polyaniline/(Ta2O5–SnO2) hybrid nanocomposite for efficient room temperature CO gas sensing

“…Some studies have proven that defects in terms of vacancies, dislocation of atoms, interstitial atoms contribute greatly in augmenting sensing response. [40][41][42] The defect centers provide active sites for chemical activity.…”