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Engineering Efficient p‐Type TMD/Metal Contacts Using Fluorographene as a Buffer Layer
Author(s) -
Musso Tiziana,
Kumar Priyank V.,
Grossman Jeffrey C.,
Foster Adam S.
Publication year - 2017
Publication title -
advanced electronic materials
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.25
H-Index - 56
ISSN - 2199-160X
DOI - 10.1002/aelm.201600318
Subject(s) - ohmic contact , work function , materials science , stoichiometry , semiconductor , buffer (optical fiber) , metal , transistor , transition metal , fermi level , monolayer , optoelectronics , layer (electronics) , nanotechnology , chemistry , electrical engineering , electron , metallurgy , physics , biochemistry , engineering , quantum mechanics , voltage , catalysis
P‐type transistors based on high work function transition metal dichalcogenide (TMD) monolayers such as MoS 2 are to date difficult to produce, owing to the strong Fermi level pinning at the semiconductor/contact metal interfaces. In this work, the potential of halogenated graphenes is demonstrated as a new class of efficient hole injection layers to TMDs such as MoS 2 and WSe 2 by taking fluorographene (or GF) as a model buffer layer. Using first‐principles computations, two commonly obtained GF stoichiometries, C 2 F and CF, have been studied as buffer layers between MoS 2 and Pt. In particular, for high work function TMDs such as MoS 2 , it has been shown that C 2 F forms an ohmic contact, while CF leads to a significant p‐SBH value. On the other hand, for low work function TMDs such as WSe 2 , both C 2 F and CF lead to p‐type ohmic contacts. This analysis shows that the ability of these buffer layers to form p‐type contacts depends crucially on the charge redistribution at the GF/metal interface, which is dictated by their chemical interaction and equilibrium geometry. The fundamental electronic structures between the different semiconductor/insulator/metal interfaces which are part of this study have also been investigated.