Metal–organic interfaces at the nanoscale

Abstract

In this work, we present an investigation of the Ag–PPP (polyparaphenylene)interface using ballistic electron emission microscopy. Our work is the first successfulapplication of the BEEM technique to metal–organic interfaces. We observe nanometrescale injection inhomogeneities. They have an electronic origin, since we findcorresponding Schottky barrier variations. We also determine the transmissionfunction of the Ag–PPP interface and find that it agrees qualitatively with thetheoretical calculations for a metal–phenyl ring interface. We conclude that chargetransport across inhomogeneous barriers needs to be considered to understandelectronic transport across metal–organic interfaces and organic device characteristics.