Generation of empirical pseudopotentials for transport applications and their application to group IV materials

Autor: William G. Vandenberghe, Maarten L. Van de Put, Akash Laturia
Rok vydání: 2020
Předmět:
Zdroj: Journal of Applied Physics. 128:034306
ISSN: 1089-7550
0021-8979
DOI: 10.1063/5.0009838
Popis: Empirical pseudopotentials (EPs) allow for accurate and efficient modeling of atomistic electron transport. Unfortunately, EPs are available only for a few materials and atomic configurations. Furthermore, EPs for nanostructures have historically been described using a variety of different parameterized forms. To compete with more general first-principles methods, we propose an automated workflow to generate EPs of a general form for any material and atomistic configuration. In particular, we focus on the generation of EPs for electron transport calculations, i.e., we provide an EP that accurately reproduces a reference band structure. To demonstrate the applicability of the proposed method, we generate the EPs to reproduce the band structure for bulk Si, Ge, 3C–SiC (zinc-blende polytype), 4H–SiC (hexagonal polytype), diamond, and hydrogen terminated ⟨ 100 ⟩ oriented Si and Ge thin films, calculated using first principles. In addition, using the generated EPs, along with the virtual crystal approximation, we demonstrate that our method reproduces accurately the band structure related properties of Si 1 − x Ge x alloy as a function of Ge mole fraction, x. As an application of our generated EPs, we perform ballistic quantum transport simulations of extremely scaled ( ≈ 0.6 nm wide), hydrogen terminated, ⟨ 100 ⟩ oriented Ge and Si gate-all-around nanowire field-effect transistors and compare their transfer characteristics.
Databáze: OpenAIRE
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