title: Formation of an interphase layer during deposition of cobalt onto tetraphenylporphyrin: a hard X-ray photoelectron spectroscopy (HAXPES) study.
abstract: The interface formation upon vapor deposition of a metal onto a molecular organic semiconductor was studied using a well-defined complexation reaction between a metal and a porphyrin. Specifically, metallic cobalt (Co) was vapor deposited onto a thin film of 2H-tetraphenylporphyrin (2HTPP) at room temperature. The resulting interface was probed with Hard X-ray Photoelectron Spectroscopy (HAXPES) using photon energies between 2 and 6 keV to obtain a detailed depth profile of the chemical composition. Characteristic changes in the N 1s core level signals reveal the formation of a cobalt tetraphenylporphyrin (CoTPP) layer between the Co and 2HTPP layers. Assuming an abrupt interface between CoTPP and 2HTPP (layer-by-layer model), analysis of the XPS data results in a thickness of the CoTPP reaction layer of 1.6 nm. However, a more advanced numerical analysis allowed us to reconstruct details of the actual depth distribution of the CoTPP interphase layer: up to a depth of 1.5 nm, all 2HTPP molecules were converted into CoTPP. Beyond this depth, the CoTPP concentration decreases sharply within 0.15 nm to zero.
authors: Fachbereich Chemie, Philipps-Universität Marburg, Hans-Meerwein-Straße 4, 35032 Marburg, Germany. michael.gottfried@chemie.uni-marburg.de.
authors: Min
authors: M
authors: Chen
authors: Fachbereich Chemie, Philipps-Universität Marburg, Hans-Meerwein-Straße 4, 35032 Marburg, Germany. michael.gottfried@chemie.uni-marburg.de.
authors: Han
authors: H
authors: Zhou
authors: Fachbereich Chemie, Philipps-Universität Marburg, Hans-Meerwein-Straße 4, 35032 Marburg, Germany. michael.gottfried@chemie.uni-marburg.de.
authors: Benedikt P
authors: BP
authors: Klein
authors: Fachbereich Chemie, Philipps-Universität Marburg, Hans-Meerwein-Straße 4, 35032 Marburg, Germany. michael.gottfried@chemie.uni-marburg.de.
authors: Malte
authors: M
authors: Zugermeier
authors: Fachbereich Chemie, Philipps-Universität Marburg, Hans-Meerwein-Straße 4, 35032 Marburg, Germany. michael.gottfried@chemie.uni-marburg.de.
authors: Claudio K
authors: CK
authors: Krug
authors: Fachbereich Chemie, Philipps-Universität Marburg, Hans-Meerwein-Straße 4, 35032 Marburg, Germany. michael.gottfried@chemie.uni-marburg.de.
authors: Hans-Jörg
authors: HJ
authors: Drescher
authors: Helmholtz Zentrum Berlin für Materialien und Energie GmbH, Albert-Einstein Str. 15, 12489 Berlin, Germany.
authors: Mihaela
authors: M
authors: Gorgoi
authors: Fachbereich Chemie, Philipps-Universität Marburg, Hans-Meerwein-Straße 4, 35032 Marburg, Germany. michael.gottfried@chemie.uni-marburg.de.
authors: Martin
authors: M
authors: Schmid
authors: Fachbereich Chemie, Philipps-Universität Marburg, Hans-Meerwein-Straße 4, 35032 Marburg, Germany. michael.gottfried@chemie.uni-marburg.de.
authors: J Michael
authors: JM
authors: Gottfried