Band alignment at interfaces of few-monolayer MoS2 with SiO2 and HfO2

Internal photoemission of electrons from 4- and 2-monolayer thick MoS2 films prepared by sulphurization of metallic Mo on top of SiO2 or HfO2/SiO2 insulating stacks is detected. This enables determination of the energy position of the MoS2 valence band which is found to be at 4.1-4.2 eV below the SiO2 conduction band. At the interface with HfO2, a barrier height of 3.7 eV is found, corresponding to an increase of the electron affinity of MoS2 by 0.5 eV as compared to the SiO2 case. This suggests the presence of interface charges (or dipoles) in the interfacial HfO2 layer. publisher: Elsevier articletitle: Band alignment at interfaces of few-monolayer MoS2 with SiO2 and HfO2 journaltitle: Microelectronic Engineering articlelink: http://dx.doi.org/10.1016/j.mee.2015.04.106 content_type: article copyright: Copyright © 2015 Elsevier B.V. All rights reserved. ispartof: Microelectronic Engineering vol:147 pages:294-297 ispartof: location:ITALY, Udine status: published