# First principles calculations of the interface properties of amorphous-Al2O3/MoS2 under non-strain and biaxial strain conditions

## TL;DR

This study uses first principles calculations to analyze the interface properties of amorphous-Al2O3 and MoS2 under different strain conditions, revealing how strain affects band alignment and potential leakage currents in MOS devices.

## Contribution

It provides a detailed first-principles analysis of the amorphous-Al2O3/MoS2 interface, including band offset calculations and strain effects, which is novel for this material combination.

## Key findings

- Valence and conduction band offsets vary with MoS2 layer number.
- Biaxial strain influences band alignment and electronic properties.
- Strain range from -6% to 6% significantly impacts interface behavior.

## Abstract

Al2O3 is a potential dielectric material for metal-oxide-semiconductor (MOS) devices. Al2O3 films deposited on semiconductors usually exhibit amorphous due to lattice mismatch. Compared to two-dimensional graphene, MoS2 is a typical semiconductor, therefore, it has more extensive application. The amorphous-Al2O3/MoS2 (a-Al2O3/MoS2) interface has attracted people's attention because of its unique properties. In this paper, the interface behaviors of a-Al2O3/MoS2 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-Al2O3 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-Al2O3/MoS2 interface. It is found that the valence band offset (VBO) and conduction band offset (CBO) change with the number of MoS2 layers. The dependence of leakage current on the band offset is also illustrated. At last, the band structure of monolayer MoS2 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.