6533b7d7fe1ef96bd1268da5

RESEARCH PRODUCT

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subject

Standing waveMaterials scienceX-ray photoelectron spectroscopyChemical physicsX-ray standing wavesCoinage metalsGeneral Materials ScienceWork functionDensity functional theorySubstrate (electronics)Condensed Matter PhysicsUltraviolet photoelectron spectroscopy

description

Energy-level alignment at organic-metal interfaces plays a crucial role for the performance of organic electronic devices. However, reliable models to predict energetics at strongly coupled interfaces are still lacking. We elucidate contact formation of 1,2,5,6,9,10-coronenehexone (COHON) to the (1 1 1)-surfaces of coinage metals by means of ultraviolet photoelectron spectroscopy, x-ray photoelectron spectroscopy, the x-ray standing wave technique, and density functional theory calculations. While for low COHON thicknesses, the work-functions of the systems vary considerably, for thicker organic films Fermi-level pinning leads to identical work functions of 5.2 eV for all COHON-covered metals irrespective of the pristine substrate work function and the interfacial interaction strength.