Electrical contact characteristics and regulatory effects of GaN/VSe₂ van der Waals heterojunction

Abstract

Reducing the Schottky barrier at the metal-semiconductor interface and achieving ohmic contacts are very important for developing high-performance Schottky field-effect devices. Base on the fact that GaN and 1T-VSe<sub>2</sub> monolayers have been successfully prepared experimentally, we theoretically construct a GaN/1T-VSe<sub>2</sub> heterojunction model and investigate its stability, Schottky barrier property and its modulation effects by using first-principle method. The calculated formation energy and the molecular dynamics simulations show that the constructed heterojunction is very stable, meaning that it can be realized experimentally. The intrinsic heterojunction holds a p-type Schottky contact and always remains an unchanged p-type Schottky contact when tensile or compressive strain is applied. But when the external electric field is applied, the situation is different, for example, a higher forward electric field can cause the heterojunction changed from a Schottky contact to an ohmic contact, and a higher reverse electric field can lead to a variation from a p-type Schottky contact to an n-type Schottky contact. In particular, by implementing chemical doping, the transition from Schottky contact to ohmic contact can be achieved more easily for the heterojunction, for example, the introduction of B atomic enables the GaN/1T-VSe<sub>2</sub> heterojunction to realize a typical ohmic contact, while for C and F atom doping, it enables the GaN/1T-VSe<sub>2</sub> heterojunction to obtain a quasi-ohmic contact. These studies provide a theoretical reference for the practical application of the suggested heterojunction, and are of very important for designing novel high-performance nano-scale electronic devices.

Electronic properties and modulation effects on edge-modified GeS₂ nanoribbons

“…的 第 一 性 原 理 方 法 . 所 有 这 些 计 算 均 在 ATK (Atomistix ToolKit)软件包 [24] 中实现, 它已被广 泛应用于研究纳米结构 [25][26][27][28][29][30] 计算中, 选择广义梯 度近似的PBE (Perdew-Burke-Ernzerhof) 函数 [31] 作 为 交 换 关 联 势 . 用 Troullier-Martin模 守 恒 赝 势 [32] 描述原子核和价电子的相互作用.…”