Quasiparticle self-consistent GW band structure of CrN

Abstract

The band structures of CrN are calculated using the quasiparticle self-consistent GW approach in both the low temperature AFM [110]2 P mna orthorhombic phase and in a hypothetical ferromagnetic phase representing the paramagnetic cubic state in a saturating magnetic field. A gap of about 1 eV is found in the AFM state, while the FM band structure is found to be half-metallic. Another hypothetical AFM-1 structure [001]1 is also considered and gives a smaller band gap. The orbital nature of the bands is studied and reveals a gap between Cr-d states, indicating a strongly correlated behavior. Optical dielectric functions are calculated from the interband transitions and compared to experimental data.

Electrochemically probing exciton transport in monolayers of two-dimensional semiconductors

“…At the monolayer limit, photogenerated carriers in TMDs become excitonic in nature due to strong connement in the xy-plane and weak dielectric screening, resulting in strong exciton binding energies on the order of several hundred meV. [15][16][17][18][19][20] This presents unique challenges in optoelectronic applications, as excitons are neutral carriers which cannot be directly inuenced by applied elds. Excitons thus move primarily via diffusion, so understanding this process, and how different structural motifs/defects within TMDs affect it, is of critical importance.…”

Janus MoSO and MoSSe Monolayers: A Promising Material for Solar Cells and Photocatalytic Applications

“…For instance, the electronic and photocatalytic properties have been altered in monolayer PdPSeX (X = O, S, and Te), [ 26 ] AlBrSe, [ 27 ] and ZnI 2 /CdS heterostructure. [ 28 ] After the tremendous work of Cheiwchanchamnangiij [ 29 ] and Ramasubramaniame, [ 30 ] it is known that the excitonic behavior also plays a vital role in determining the physical properties of TMDs. However, a systematic theoretical study of the Janus MoXY is required for both fundamental research and application perspectives, which is still lacking in the literature.…”

Strain and thickness effects on the electronic structures of low-energy two-dimensional CdxTey phases

“…For an accurate determination of the band gap, the band structure calculated using a hybrid functional (HSE06) is also shown as the PBE functional underestimates it. Contrary to transition metal dichalcogenides (TMDCs), which switch from the direct to indirect band gap when its thickness changes from SL to BL, 49 CdTe retains its direct band gap in all forms, i.e., SL, BL, TL, and bulk. The robustness of the direct band gap towards the thickness of a sheet is an excellent property because controlling the thickness to exactly SL throughout the entire area of a wafer-scale sheet is a challenging task.…”