Phonon scattering limited performance of monolayer MoS2 and WSe2 n-MOSFET

Sengupta, A. , Chanana, A. and Mahapatra, S. (2015) Phonon scattering limited performance of monolayer MoS2 and WSe2 n-MOSFET. AIP Advances, 5(2), 027101. (doi: 10.1063/1.4907697)

Abstract

In this paper we show the effect of electron-phonon scattering on the performance of monolayer (1L) MoS2 and WSe2 channel based n-MOSFETs. Electronic properties of the channel materials are evaluated using the local density approximation (LDA) in density functional theory (DFT). For phonon dispersion we employ the small displacement / frozen phonon calculations in DFT. Thereafter using the non-equilibrium Green’s function (NEGF) formalism, we study the effect of electron-phonon scattering and the contribution of various phonon modes on the performance of such devices. It is found that the performance of the WSe2 device is less impacted by phonon scattering, showing a ballisticity of 83% for 1L-WSe2 FET for channel length of 10 nm. Though 1L-MoS2 FET of similar dimension shows a lesser ballisticity of 75%. Also in the presence of scattering there exist a a 21–36% increase in the intrinsic delay time (τ) and a 10–18% reduction in peak transconductance (gm) for WSe2 and MoS2 devices respectively.

• Item Type: Articles
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Sengupta, Dr Amretashis
• Authors: Sengupta, A., Chanana, A., and Mahapatra, S.
• College/School: College of Science and Engineering > School of Engineering > Systems Power and Energy
• Journal Name: AIP Advances
• Publisher: AIP Publishing
• ISSN: 2158-3226
• ISSN (Online): 2158-3226
• Published Online: 05 February 2015
• Copyright Holders: Copyright © 2015 The Authors
• First Published: First published in AIP Advances 5(2):027101
• Publisher Policy: Reproduced under a Creative Commons License

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