arXiv subjects

Rafael Furlan de Oliveira

Publications and source records attributed to Rafael Furlan de Oliveira.

2 recordsLinked to original sources

arXiv2025

Frequency as a Clock: Synchronization and Intrinsic Recovery in Graphene Transistor Dynamics

Hysteresis and memory effects in graphene field-effect transistors (GFETs) offer unique opportunities for neuromorphic computing, sensing, and memory applications, yet their physical origins remain debated due to competing volatile and nonvolatile interpretations. Here, we present a unified dynamic model that captures the essential physics of the GFET response under periodic gate modulation, accounting for both intrinsic relaxation processes and externally driven charge transfer. By modeling non-equilibrium carrier dynamics as a competition between injection and reabsorption rates, we uncover two distinct regimes: one governed by intrinsic, frequency-independent relaxation and another exhibiting frequency-locked behavior where the response is tied to the external drive. This distinction resolves apparent nonvolatile effects and explains loop invariance in floating-gate structures via displacement current-driven charge injection. Our framework predicts the evolution of the hysteresis loop shape, amplitude, and direction across a wide range of driving conditions, offering a versatile tool for interpreting experimental results and guiding the design of next-generation graphene-based electronic systems.

cond-mat.mes-hall↗

arXiv2022

The role of functional thiolated molecules on the enhanced electronic transport of interconnected MoS$_2$ nanostructures

Molecular linkers have emerged as an effective strategy to improve electronic transport properties on solution-processed layered materials via defect functionalization. However, a detailed discussion on the microscopic mechanisms behind the beneficial effects of functionalization is still missing. Here, by first-principles calculations based on density functional theory, we investigate the effects on the electronic properties of interconnected MoS$_2$ model flakes systems upon functionalization with different thiol molecule linkers, namely thiophenol, 1,4-benzenedithiol, 1,2-ethanedithiol, and 1,3-propanedithiol. The bonding of benzene- and ethanedithiol bridging adjacent armchair MoS$_2$ nanoflakes leads to electronic states just above or at the Fermi level, thus forming a molecular channel for electronic transport between flakes. In addition, the molecular linker reduces the potential barrier for thermally activated hopping between neighboring flakes, improving the conductivity as verified in experiments. The comprehension of such mechanisms helps in future developments of solution-processed layered materials for use on 2D electronic devices.

cond-mat.mtrl-sci↗