Hybrid molecular graphene transistor as an operando and optoelectronic platform.

Lack of reproducibility hampers molecular devices integration into large-scale circuits. Thus, incorporating operando characterization can facilitate the understanding of multiple features producing disparities in different devices. In this work, we report the realization of hybrid molecular graphene field effect transistors (m-GFETs) based on 11-(Ferrocenyl)undecanethiol (FcCSH) micro self-assembled monolayers (μSAMs) and high-quality graphene (Gr) in a back-gated configuration.

Rectification Ratio and Tunneling Decay Coefficient Depend on the Contact Geometry Revealed by in Situ Imaging of the Formation of EGaIn Junctions.

This paper describes how the intensive (tunneling decay coefficient β and rectification ratio R) and extensive (current density J) properties of Ag-S(CH) CH//GaO /EGaIn junctions ( n = 10, 14, 18) and molecular diodes of the form of Ag-S(CH)Fc//GaO /EGaIn depend on A, the contact area between the self-assembled monolayer and the cone-shaped EGaIn tip. Large junctions with A ≥ 1000 μm are unreliable and defects, such as pinholes, dominate the charge transport characteristics. For S(CH)Fc SAMs, R decreases from 130 to unity with increasing A due to an increase in the leakage current (the current flowing across the junction at reverse bias when the diodes block current flow).

Electrochemical Imaging of Dense Molecular Nanoarrays.

The aim of the present work is to explore the combination of atomic force electrochemical microscopy, operated in molecule touching mode (Mt/AFM-SECM), and of dense nanodot arrays, for designing an electrochemically addressable molecular nanoarray platform. A high density nanoarray of single grained gold nanodots (∼15 nm-diameter nanoparticles, 100 nm pitch) is decorated by a model molecular system, consisting of ferrocene (Fc) labeled polyethylene glycol (PEG) disulfide chains. We show that the high resolution of Mt/AFM-SECM enables the electrochemical interrogation of several hundreds of individual nanodots in a single image acquisition.

High speed e-beam lithography for gold nanoarray fabrication and use in nanotechnology.

E-beam lithography has been used for reliable and versatile fabrication of sub-15 nm single-crystal gold nanoarrays and led to convincing applications in nanotechnology. However, so far this technique was either too slow for centimeter to wafer-scale writing or fast enough with the so-called dot on the fly (DOTF) technique but not optimized for sub-15 nm dots dimension. This prevents use of this technology for some applications and characterization techniques.