We have investigated the structural, electronic and thermoelectric properties of GaS, GaSe and GaTe monolayers based on the first-principles approach by using density functional theory and the semi-classical Boltzmann transport equation.

The ground-state behavior of the symmetric electron-electron and electron-hole bilayers is studied by including dynamic correlation effects within the quantum version of Singwi, Tosi, Land, and Sjölander (qSTLS) theory. The static pair-correlation functions, the local-field correction factors, and the ground-state energy are calculated over a wide range of carrier density and layer spacing. The possibility of a phase transition into a density-modulated ground state is also investigated. Results for both the electron-electron and electron-hole bilayers are compared with those of recent diffusion Monte Carlo (DMC) simulation studies. We find that the qSTLS results differ markedly from those of the conventional STLS approach and compare in the overall more favorably with the DMC predictions. An important result is that the qSTLS theory signals a phase transition from the liquid to the coupled Wigner crystal ground state, in both the electron-electron and electron-hole bilayers, below a critical density and in the close proximity of layers (d < ∼ rsa * 0 ), in qualitative agreement with the findings of the DMC simulations.

No abstract

We investigate the electronic properties of two-dimensional buckled honeycomb GaAs in the presence of an external electric field using first principles calculations.

No abstract