Graphene is a breakthrough 2D material due to its unique mechanical, electrical, and thermal properties, with considerable responsiveness in real applications. However, the coverage of large areas with pristine graphene is a challenge and graphene derivatives have been alternatively exploited to produce hybrid and composite materials that allow for new developments, considering also the handling of large areas using distinct methodologies. For electronic applications there is significant interest in the investigation of the electrical properties of graphene derivatives and related composites to determine whether the characteristic 2D charge transport of pristine graphene is preserved. Here, we report a systematic study of the charge transport mechanisms of reduced graphene oxide chemically functionalized with sodium polystyrene sulfonate (PSS), named as GPSS. GPSS was produced either as quantum dots (QDs) or nanoplatelets (NPLs), being further nanostructured with poly(diallyldimethylammonium chloride) through the layer-by-layer (LbL) assembly to produce graphene nanocomposites with molecular level control. Current-voltage (I-V) measurements indicated a meticulous growth of the LbL nanostructures onto gold interdigitated electrodes (IDEs), with a space-charge-limited current dominated by a Mott-variable range hopping mechanism. A 2D intra-planar conduction within the GPSS nanostructure was observed, which resulted in effective charge carrier mobility (μ) of 4.7 cm V s for the QDs and 34.7 cm V s for the NPLs. The LbL assemblies together with the dimension of the materials (QDs or NPLs) were favorably used for the fine tuning and control of the charge carrier mobility inside the LbL nanostructures. Such 2D charge conduction mechanism and high μ values inside an interlocked multilayered assembly containing graphene-based nanocomposites are of great interest for organic devices and functionalization of interfaces.

The rise of graphene as an innovative electronic material promoted the study and development of new 2-D materials. Among them, reduced graphene oxide (rGO) appears like an easy and cost-effective solution for the fabrication of thin-film transistors (TFTs). To understand the limits and possible application fields of rGO-based TFTs, a proper estimation of the device parameters is of extreme importance. In this work, liquid-gated ambipolar rGO-TFTs are characterized and a description of their working principle is given. Particular attention is paid toward the importance of the transistors' OFF-state conductivity that was modeled as a resistance connected in parallel with the TFT. Thanks to this model, the main transistor parameters were extrapolated from rGO-TFTs with different levels of electrochemical reduction. The extracted parameters allowed understanding that rGO-TFTs have similar holes and electrons mobilities, and the more pronounced p-type behavior of the devices is due to a positive shift in the p-type and n-type threshold voltages.

I N THE above article [1], an error is present in (1). The correct equation should read as in ( 1), shown at the bottom of the page. This is the equation that was used to extrapolate the fitting parameters reported in Table II and to draw the fitting curve reported in Fig. 6. Therefore, the scientific results and conclusions in the original manuscript do not change.

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Electrodeposition of Cu coatings onto the gates of electrolyte-gated transistors based on reduced graphene oxide leads to efficient devices featuring a sensitivity equal to 1–3 mV and able to track emulated action potentials (frequency 0.1 Hz).