Blends of reduced graphene oxide (RGO) and poly(3-hexylthiophene) (P3HT) are used as the active layer of field-effect transistors (FETs). By using sequential deposition of the two components, the density of RGO sheets can be tuned linearly, thereby modulating their contribution to the charge transport in the transistors, and the onset of charge percolation. The surface potential of RGO, P3HT and source–drain contacts is measured on the nanometric scale with Kelvin Probe Force Microscopy (KPFM), and correlated with the macroscopic performance of the FETs. KPFM is also used to monitor the potential decay along the channel in the working FETs.

Although the growth of graphene by chemical vapor deposition is a production technique that guarantees high crystallinity and superior electronic properties on large areas, it is still a challenge for manufacturers to efficiently scale up the production to the industrial scale. In this context, issues related to the purity and reproducibility of the graphene batches exist and need to be tackled. When graphene is grown in quartz furnaces, in particular, it is common to end up with samples contaminated by heterogeneous particles, which alter the growth mechanism and affect graphene’s properties. In this paper, we fully unveil the source of such contaminations and explain how they create during the growth process. We further propose a modification of the widely used quartz furnace configuration to fully suppress the sample contamination and obtain identical and clean graphene batches on large areas.

Supersaturated solutions of substitutional, electrically active Sb in 〈100〉 silicon single crystals have been obtained by ion implantation, followed by short‐duration incoherent‐light annealing. Substitutional and nonsubstitutional fractions have been studied as functions of implanted dose and anneal temperature by Rutherford backscattering and channeling techniques, transmission‐electron microscopy, Hall‐effect and resistivity measurements (combined with layer removal), and Mössbauer spectroscopy. The maximum electrically active concentration, which can be incorporated on undisturbed substitutional sites, is found to be 4.5×10²⁰ Sb/cm³ for 700 °C annealing. Upon further annealing, the supersaturated solution is reduced and approaches the Trumbore solubility value at temperatures of about 1100 °C. The Sb going out of solution is shown for the first time to be created in two different surroundings: Sb is predominantly found in Sb‐vacancy complexes for low doses and low annealing temperatures and in Sb precipitates for high doses and/or high annealing temperatures. Complete agreement is found between substitutional fractions derived from Mössbauer spectroscopy and electrically active fractions from Hall‐effect measurements, whereas the substitutional fractions from channeling measurements are significantly higher. The experiments are not conclusive as to whether this difference is due to the fraction of Sb in Sb‐vacancy complexes or in coherent Sb precipitates.

High-electronic quality hydrogenated amorphous silicon-nitrogen (a-Si1-xNx: H) films with an energy gap in the range 1.9-2.7eV have been deposited by plasma-enhanced chemical vapour deposition in silane-ammonia gas mixtures at two different gas residence times and in hydrogen-diluted silane-ammonia gas mixtures. Compositional, structural, electrical and optical properties have been investigated. For the first time the effects of hydrogen dilution of SiH4 + NH3 gas mixtures on the a-Si1-xNx: H network is reported. We have observed that hydrogen dilution decreases hydrogen incorporation and increases nitrogen incorporation, promoting a higher connectivity of the a-Si1-xNx :H network. All films show good electronic properties, comparable with or superior to those of amorphous silicon-carbon films, which are improved in films deposited from hydrogen-diluted gas mixtures