Non-volatile resistive switching mechanism in single-layer MoS memristors: insights from modelling of Au and MoS interfaces.

Non-volatile memristive devices based on two-dimensional (2D) layered materials provide an attractive alternative to conventional flash memory chips. Single-layer semiconductors, such as monolayer molybdenum disulphide (ML-MoS), enable the aggressive downscaling of devices towards greater system integration density. The "atomristor", the most compact device to date, has been shown to undergo a resistive switching between its high-resistance (HRS) and low-resistance (LRS) states of several orders of magnitude.

Capillary-force-driven self-assembly of carbon nanotubes: from calculations to modeling of self-assembly.

In elasto-capillary driven self-assembly of arrays of carbon nanotubes (CNTs) different factors play a role, from the mechanical properties of CNTs to the array geometry. In this work, we provide a multi-scale investigation where we first use density functional theory (DFT) to predict fully relevant mechanical properties such as Young's modulus, Poisson's ratio, and surface energy. To the best of our knowledge, we are the first to report DFT calculations of the surface energy of CNTs.

Assessing doping strategies for monolayer MoS towards non-enzymatic detection of cortisol: a first-principles study.

In this work, we investigate by means of atomistic density functional theory simulations the interaction between cortisol (the target molecule) and monolayer MoS (the substrate). The aim is to assess viable strategies for the non-enzymatic chemical sensing of cortisol. Metal doping of the sensing material could offer a way to improve the device response upon analyte adsorption, and could also enable novel and alternative detection mechanisms.

Linear-scaling density functional simulations of the effect of crystallographic structure on the electronic and optical properties of fullerene solvates.

In this work, the crystal properties, HOMO and LUMO energies, band gaps, density of states, as well as the optical absorption spectra of fullerene C and its derivative phenyl-C-butyric-acid-methyl-ester (PCBM) co-crystallised with various solvents such as benzene, biphenyl, cyclohexane, and chlorobenzene were investigated computationally using linear-scaling density functional theory with plane waves as implemented in the ONETEP program. Such solvates are useful materials as electron acceptors for organic photovoltaic (OPV) devices. We found that the fullerene parts contained in the solvates are unstable without solvents, and the interactions between fullerene and solvent molecules in C and PCBM solvates make a significant contribution to the cohesive energies of solvates, indicating that solvent molecules are essential to keep C and PCBM solvates stable.

Ab initio modeling of 2D layered organohalide lead perovskites.

A number of 2D layered perovskites A2PbI4 and BPbI4, with A and B mono- and divalent ammonium and imidazolium cations, have been modeled with different theoretical methods. The periodic structures have been optimized (both in monoclinic and in triclinic systems, corresponding to eclipsed and staggered arrangements of the inorganic layers) at the DFT level, with hybrid functionals, Gaussian-type orbitals and dispersion energy corrections. With the same methods, the various contributions to the solid stabilization energy have been discussed, separating electrostatic and dispersion energies, organic-organic intralayer interactions and H-bonding effects, when applicable.