AbstractSelf-assembled monolayers of fluorinated thiols have been used as a means of surface conditioning to modify the work function of polycrystalline, wide-gap, chalcopyrite thin films. The molecular dipole, characteristic of such polar molecules, could be transferred to the surface of the semiconductor. Self-arrangement and orientation of the molecules upon adsorption ensured a net dipole contribution that was observed by means of ultra-violet photoemission spectroscopy. Such an approach offers a simple way for interface engineering, with a potential impact on the design of compound-specific band alignments of chalcopyrite-based devices. Molecular mechanics calculations of the expected molecular geometries complemented this work.