In this work, we investigate the transverse transport properties of few-layers MoS2 using a Conductive Atomic Force Microscopy based technique. We find that the system changes between a low-force regime, characterized by a nearly-ideal contact between the MoS2 flake and the substrate, and a high-force regime, for which this contact starts to become highly non-ideal. We propose a 3-diode model that effectively describes the current-voltage characteristics of few-layers MoS2. From this model, we estimate how fast the energy gaps of two-dimensional MoS2 materials change as a function of the applied force. From our analysis, we estimate that MoS2-Au Schottky barrier heights change at the rate of 0.21, 0.23, and 0.78 meV nN−1 for the few-layers, three-layers, and two-layers MoS2, respectively. Our work opens up new possibilities of investigating and controlling the electronic properties of 2D semiconducting materials.

Understanding the thermodynamic properties of materials is a fundamental issue in physics, and its knowledge is crucial for targeting a specific material for possible applications. In this work, we report a temperature‐ and pressure‐dependent Raman study of bulk GaSe0.5Te0.5 alloy, besides their relevant thermodynamic parameters. Our results show a nonlinear redshift for the A1g and E2g vibrational modes as the temperature increases in the temperature range from 10 to 748 K. Such behavior is well described by considering both thermal expansion and phonon–phonon coupling contributions. By combining density functional theory (DFT) calculations and Raman spectroscopy experiments, the anharmonic constants relative to the three‐ and four‐phonon decay processes, mode‐Grüneisen parameters, Debye temperature, thermal expansion coefficient, and bulk modulus were estimated for GaSe0.5Te0.5 alloy. Furthermore, the high‐pressure measurements and DFT calculations, performed in the pressure range from 0 to 26.4 GPa, show a quadratic trend for the ωA1g and ωE2g modes as a function of pressure, with the A1g modes being more compressible than E2g one, that is, ∂ωA1g∂P>∂ωE2g∂P. No structural phase transition is observed until the maximum pressure reached in the experiment. This study took a step forward in the understanding of mechanical and thermal properties related to GaSe0.5Te0.5 alloy, whose determined parameters are important for designing new applications.

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Among the most studied semiconducting transition metal dichalcogenides (TMDCs), WS2 showed several advantages in comparison to their counterparts, such as a higher quantum yield, which is an important feature for quantum emission and lasing purposes. We studied transferred monolayers of WS2 on a drilled Si3N4 substrate in order to have insights about on how such heterostructure behaves from the Raman and photoluminescence (PL) measurements point of view. Our experimental findings showed that the Si3N4 substrate influences the optical properties of single-layer WS2. Beyond that, seeking to shed light on the causes of the PL quenching observed experimentally, we developed density functional theory (DFT) based calculations to study the thermodynamic stability of the heterojunction through quantum molecular dynamics (QMD) simulations as well as the electronic alignment of the energy levels in both materials. Our analysis showed that along with strain, a charge transfer mechanism plays an important role for the PL decrease.