Designing high-efficiency metal and semimetal contacts to two-dimensional semiconductor γ-GeSe

Autor: Liemao Cao, Xiaohui Deng, Zhenkun Tang, Guanghui Zhou, Yee Sin Ang
Rok vydání: 2022
Předmět:
Zdroj: Applied Physics Letters. 121:113104
ISSN: 1077-3118
0003-6951
DOI: 10.1063/5.0117670
Popis: Forming a low-resistance semiconductor–metal contact is a critical step to achieve a high-performance two-dimensional (2D) semiconductor nanoelectronic device. Motivated by the recent discovery of monolayer γ-GeSe with exceptional high electrical conductivity reaching 105 S/m, we computationally investigate the interface contact properties of γ-GeSe with four representative classes of metallic systems, including 2D semimetal (graphene), 2D metal (NbS2), 3D semimetal (Bi), and 3D metal (Au) using first-principle density functional theory simulations. We found that these metals exhibit rich contact formation physics with 2D γ-GeSe, yielding contacts of heterostructures with weak and moderate couplings. Importantly, γ-GeSe/NbS2 is an Ohmic contact while γ-GeSe/Bi is an n-type Schottky contact with an ultralow barrier height of 0.07 eV. For γ-GeSe/graphene contact, the electronic properties can be adjusted via the interlayer distance or via an external electric field. Finally, we show that the contact properties can also be further controlled using layer-number engineering of γ-GeSe. Our findings provide a useful guideline for designing high-performance 2D nanoelectronics based on 2D γ-GeSe.
Databáze: OpenAIRE