Phonon-assisted transport in van der Waals heterostructure tunnel devices

• Published in: Solid-state electronics Vol. 194; p. 108344
• Main Authors: M'foukh, A., Saint-Martin, J., Dollfus, P., Pala, M.
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.08.2022; Elsevier
• Subjects: Condensed Matter; DFT; Electron-phonon interaction; Engineering Sciences; Materials Science; Mesoscopic Systems and Quantum Hall Effect; Micro and nanotechnologies; Microelectronics; Non equilibrium Green’s function; Physics; Tunnel FET; Van der Waals heterostructure; Van der Waals heterostructure; Electron-phonon interaction; DFT; Tunnel FET; Non equilibrium Green’s function
• ISSN: 0038-1101; 1879-2405
• DOI: 10.1016/j.sse.2022.108344

•A theoretical study of dissipative transport in vdW TFETs has been addressed thanks to a full ab-initio model.•The results suggest that vdW TFETs are significantly affected by phonon scattering due to the large coupling of electrons with polar phonons.•However, they remain a promising option for the next generation electronics due to the high current around 580μA/μm and a SS of 26 mV/dec reached at low voltage with phonon coupling. In this work, we present a first-principles study of quantum transport in tunnel FETs based on van der Waals (vdW) heterostructures of transition metal dichalcogenides (TMDs). We focus on 1T-HfSe2 and 1T-SnS2 monolayers to construct a vertical heterostructure with a type-II band alignment. By including dissipative effects due to the electron–phonon interaction, we show that vdW tunnel FETs are highly sensible to the phonon coupling due to polar optical phonons present in TMDs which results in an increased sub-threshold swing (SS) and reduced ON-current. However, vdW TFETs are still able to provide high ON-current values due to the inversion of CB and VB at high VGS and high inter-valley tunneling.