| AVS 57th International Symposium & Exhibition | |
| Energy Frontiers Topical Conference | Wednesday Sessions |
| Session EN+NS-WeM |
| Session: | Organic Photovoltaics |
| Presenter: | M.M. Beerbom, University of South Florida |
| Authors: | M.M. Beerbom, University of South Florida W. Wang, University of South Florida R. Schlaf, University of South Florida |
| Correspondent: | Click to Email |
The energy level alignment between two prototypical conductive polymers, poly(3-hexylthiophene) (P3HT) and poly[2-methoxy-5-(2'-ethyl-hexyloxy)-1,4-phenylene vinylene] (MEH-PPV) and metals was investigated with ultraviolet and x-ray photoemission spectroscopy (XPS, UPS) dependent on the metal substrate work function. In these experiments thin films of the polymer material were grown in several steps on in-vacuum cleaned metal substrates. In between deposition steps the surface was characterized with UPS and XPS without breaking the vacuum. This was enabled by electrospray polymer thin film deposition directly from solution, which allows the growth of clean macro-molecular films in vacuum. This enabled the measurement of the hole injection barriers and interface dipoles unaffected by environmental contamination artifacts. The presented results demonstrate a systematic dependence of the interface dipole on the substrate work function. This indicates that the charge neutrality level-based “induced density of interface states” (IDIS) model also holds for non-reactive conductive polymer/metal interfaces.