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 successful application of the BEEM technique to metal-organic interfaces. We observe nanometer scale injection inhomogeneities. They have an electronic origin, since we find corresponding Schottky barrier variations. We also determine the transmission function of Ag-PPP interface and find that it agrees qualitatively with the theoretical calculations for a metalphenyl ring interface. We conclude that charge transport across inhomogeneous barriers needs to be considered for understanding electronic transport across metal-organic interfaces and organic device characteristics.

Ballistic Electron Emission Microscopy/Spectroscopy on Au/Titanylphthalocyanine/GaAs Heterostructures

“…4 shows averaged BEEM spectra (I t = 5 nA, T = 300 K) and the dashed line is its first derivative taken of over 100 individual BEEM spectra. The spec-tra are taken over a voltage-range of 0.8 to 2.3 V. Above the onset several features are visible, three steps at the points: 1.34, 1.52 and 1.61 V. The same behavior of metalorganic interfaces was also found in [16] - [18]. Besides these features there are two significant peaks at 1.7 and 1.85 V. Above 2.3 V the data were not reliable, because of the increased signal to noise ratio.…”

Ballistic emission microscopy studies on metal–molecule interfaces

“…Therefore, using a three-step model for BEEM [9,10], it is possible to determine the transmission function for the metal-molecule interface [51]. Comparing the normalized transmission function determined from experimental data with the calculation of Xue and Ratner [22,23] yields two common features: (a) both have a curvature that is concave upwards, i.e.…”

Ballistic electron emission spectroscopy on Ag/Si devices

“…Recently, the ballistic transport of electrons through organic molecules has been studied by BEEM [9][10][11][12].…”