title: Surface coatings based on polysilsesquioxanes: solution-processible smooth hole-injection layers for optoelectronic applications.
abstract: Optoelectronic devices usually consist of a transparent conductive oxide (TCO) as one electrode. Interfacial engineering between the TCO electrode and the overlying organic layers is an important method for tuning device performance. We introduce poly(methylsilsesquioxane)-poly(N,N-di-4-methylphenylamino styrene) (PMSSQ-PTPA) as a potential hole-injection layer forming material. Spin-coating and thermally induced crosslinking resulted in an effective planarization of the anode interface. HOMO level (-5.6 eV) and hole mobility (1 × 10(-6)  cm(2)  · Vs(-1) ) of the film on ITO substrates were measured by cyclovoltammetry and time-of-flight measurement demonstrating the hole injection capability of the layer. Adhesion and stability for further multilayer built-up could be demonstrated. Contact angle measurements and tape tests after several solvent treatments proved the outstanding film stability.
authors.affiliation: Institute of Organic Chemistry, Johannes Gutenberg University, Mainz, Duesbergweg 10-14, 55099 Mainz, Germany; Max Planck Institute for Polymer Research, Ackermannweg 10, 55128 Mainz, Germany.
authors.forename: Daniel
authors.initials: D
authors.lastname: Kessler
authors.forename: Maria C
authors.initials: MC
authors.lastname: Lechmann
authors.forename: Seunguk
authors.initials: S
authors.lastname: Noh
authors.forename: Rüdiger
authors.initials: R
authors.lastname: Berger
authors.forename: Changhee
authors.initials: C
authors.lastname: Lee
authors.forename: Jochen S
authors.initials: JS
authors.lastname: Gutmann
authors.forename: Patrick
authors.initials: P
authors.lastname: Theato