Ballistic electron emission microscopy of Au-InAs-GaAs system

We report an investigation of barrier formation and electron transport across InAs and GaAs interfaces by ballisticelectron emissionmicroscopy. The barrier height was found to decrease with the InAs thickness and the detailed variation correlates with the relaxation of the InAs layer. When the thickness is below one monolayer, three thresholds are observed and they are attributed to electron transmission into the Γ, L, and X valleys of the GaAs, respectively. As the thickness increases to three monolayers or beyond, only two thresholds are observed and the reasons are explained in the context of the band structure of the system