The electronic structure and chemical properties of organic/organic and organic/metal interfaces involving molecular semiconductors are investigated via photoemission spectroscopy. The alignment of electronic levels, electron and hole injection barriers, and interface dipoles are measured for each interface. Chemical reactions and interdiffusion dominate metal-on-organic contacts, whereas organic-on-metal and organic/organic interfaces are more abrupt. The rule of vacuum level alignment, expected to hold for organic molecular interfaces, breaks down for all metal/organic and several organic/organic interfaces, showing that electronic gap states and other interface effects cannot be neglected at these interfaces.

Date Published: 16 December 1998
PDF: 10 pages
Proc. SPIE 3476, Organic Light-Emitting Materials and Devices II, (16 December 1998); doi: 10.1117/12.332610

Published in SPIE Proceedings Vol. 3476:
Organic Light-Emitting Materials and Devices II
Zakya H. Kafafi, Editor(s)