Periodic trends in the structural, electronic, and transport properties of electrenes

Abstract

Two-dimensional layered electrides are a class of atomically thin materials in which the anion is an excess electron rather than a negatively charged ion. These excess electrons form delocalized sheets...

Intrinsic Modulation Doping Enhances the Thermoelectric Performance of Monolayer GaGeTe

“…5 From this vantage point, the Onsager coefficients, which regulate the transport distribution function, are defined as Σ(E) ∝ M(E)λ(E), where M is the density of modes and λ is the mean-free-path of backscattering electrons. 54,55 As previously noted, the "Mexican hat" causes a singularity (i.e., a sudden rise) in the vicinity of the VBM (Figure 3). According to Landauer's formulation, such singularity increases the number of conducting channels, facilitates carrier transportation, and enhances the PF of a thermoelectric material.…”

“…The benefit of Mexican hat in thermoelectricity is explained in terms of abrupt changes in the DOS, resembling a singularity near the band edges, which promotes carrier transport. − We elaborate on the transport properties of GaGeTe from a Landauer perspective . From this vantage point, the Onsager coefficients, which regulate the transport distribution function, are defined as Σ­( E ) ∝ M ( E )­λ­( E ), where M is the density of modes and λ is the mean-free-path of back-scattering electrons. , As previously noted, the “Mexican hat” causes a singularity (i.e., a sudden rise) in the vicinity of the VBM (Figure ). According to Landauer’s formulation, such singularity increases the number of conducting channels, facilitates carrier transportation, and enhances the PF of a thermoelectric material. , …”

Designing barrier-free metal/MoS2 contacts through electrene insertion

“…Fig. 3(b) shows a positive correlation between Q MoS 2 and the work function, F m , computed 42 for the monolayer electrene. This result is somewhat counterintuitive, since lower work function materials may be expected to promote more electron transfer to the semiconductor.…”

“…and the work functions (F m ) of various monolayer electrenes computed in our previous work. 42 The surface charges of the monolayer electrenes were obtained from the planar average of the integrated local density of states (ILDOS) along the z-axis, integrated over energy from the bottom of the surface bands up to the Fermi level. The averaged ILDOS was then integrated along the z-axis from the outermost metal atom to the vacuum region (where the ILDOS reaches zero) to give Q surf M 2 X .…”

“…[28][29][30][31][32][33][34][35][36][37][38][39][40][41] We have previously investigated periodic trends in the electronic, structural, and transport properties of the corresponding monolayer and bilayer electrenes. 42 In this work, we employ DFT to investigate various electrenes in contact with both Au and Cu metals and MoS 2 to determine which material is the most promising for eliminating the Schottky and tunnelling barriers in metal/MoS 2 contacts. In particular, we determine the extent to which MoS 2 conduction bands become metallized following electrene insertion and analyze the electrostatic potential at the interfaces, which should shed light on electron transport across these contacts.…”