First principles calculations of the interface properties of a-Al2O3/MoS2 and effects of biaxial strain

Abstract

Al 2 O 3 is a potential dielectric material for metal-oxide-semiconductor (MOS) devices. Al 2 O 3 films deposited on semiconductors usually exhibit amorphous due to lattice mismatch. Compared to two-dimensional graphene, MoS 2 is a typical semiconductor, therefore, it has more extensive application. The amorphousAl 2 O 3 /MoS 2 (a-Al 2 O 3 /MoS 2 ) interface has attracted people's attention because of its unique properties. In this paper, the interface behaviors of a-Al 2 O 3 /MoS 2 under non-strain and biaxial strain are investigated by first principles calculations based on density functional theory (DFT). First of all, the generation process of a-Al 2 O 3 sample is described, which is calculated by molecular dynamics and geometric optimization. Then, we introduce the band alignment method, and calculate band offset of a-Al 2 O 3 /MoS 2 interface. It is found that the valence band offset (VBO) and conduction band offset (CBO) change with the number of MoS 2 layers. The dependence of leakage current on the band offset is also illustrated. At last, the band structure of monolayer MoS 2 under biaxial strain is discussed. The biaxial strain is set in the range from -6% to 6% with the interval of 2%. Impact of the biaxial strain on the band alignment is investigated.

Tuning Schottky Barrier and Contact Type of Metal–Semiconductor in Ti3C2T2/MoS2 (T = F, O, OH) by Strain: A First-Principles Study

“…To further reflect the essence of strain regulation on interface barrier, the variation of band edge position and band gap of MoS 2 with strain in Ti 3 C 2 T 2 /MoS 2 are shown in Figure . Obviously, the band gap for MoS 2 decreases with increasing strain in all cases, which is consistent with the literature. − Furthermore, it can be seen that the VBM and CBM of MoS 2 decrease in Ti 3 C 2 F 2 /MoS 2 and Ti 3 C 2 O 2 /MoS 2 when the strain is present. In Ti 3 C 2 F 2 /MoS 2 , the VBM of MoS 2 increases with the increasing strain, which is always lower than the Fermi level.…”

Investigation of energy band at atomic layer deposited AZO/β-Ga2O3 ($$ \overline{2}01 $$) heterojunctions

“…To correct the underestimated bandgap, 35% of PBE exchange was replaced with the exact one [27]. To identify the band edge shift with the change of the Al doping level, the average electrostatic potential (AEP) was calculated and aligned to the vacuum level which was scaled to 0 V. The VBM and conduction band minimum (CBM) were consequently aligned to the AEP based on the band diagram [28]. In this work, bulk ZnO with 16 O atoms and 16 Zn atoms in the supercell was used.…”

Structures and Electromagnetic Properties of Boron Nitride Nanoribbons Doped with Transition Metals

“…For computational examples, DFT calculations using the PBE functional suggested that the MN 4 -BNNRs (M=Cr, Mn, Fe, Co, Mo, Ru and Rh), [75] which contain NÀ N bonds, have a narrow band gap from 0.51 to 1.54 eV, although those values would probably be larger if the more reliable HSE functional is used. [76,77]…”