Organic semiconductor/metal interface energetics play a key role in the performance of organic-based electronic devices. The comparative angle-resolved ultraviolet photoelectron spectroscopy (ARUPS) study of pentacene (PEN) and perfluoropentacene (PFP) on Au(111) reported here highlights the effect of perfluorination and molecular layer thickness on the interface energy levels (see figure for PFP/Au(111) interface energy levels).