Advanced characterization of organic–metal and organic–organic interfaces: from photoelectron spectroscopy data to energy-level diagrams

Abstract Organic–metal and organic–organic interfaces account for the functionality of virtually all organic optoelectronic applications energy-level alignment is particular importance device performance. Often simply estimated by metal work functions ionization energies electron affinities materials. However, various interfacial effects such as push back, mirror forces (also known screening), electronic polarization or charge transfer affect alignment. We perform x-ray ultraviolet photoelectron spectroscopy (XPS UPS) measurements on copper-hexadecafluorophthalocyanine (F 16 CuPc) titanyl-phthalocyanine (TiOPc) thin films Ag(111) use TiOPc bilayers to decouple F CuPc layers from substrate. Even our structurally well-characterized model stepwise preparation vacuum-sublimed samples, a precise assignment vacuum-level shifts remains challenging. Nevertheless, results provide guidelines interpretation XPS UPS data organic–metal interfaces.