Today’s champion organic (opto-)electronic devices, like the mobile-phone displays in your hand or the TV-screens in your home, comprise an ever-increasing number of layers of different organic molecules. The functionality of these complex heterostructures largely derives from the relative values of the discrete energies that charge carriers can have in each layer with respect to those in all other layers. Despite the technological relevance of the energy-level alignment at organic heterointerfaces, and despite continued scientific interest, however, a reliable theoretical model that can quantitatively predict the full range of phenomena observed at such interfaces is notably absent. We identify the limitations of previous attempts to formulate such a model and highlight inconsistencies in the interpretation of the experimental data they were based on. We then develop a theoretical framework, which we demonstrate to accurately reproduce experiment. Applying this theory, a comprehensive overview of all possible energy-level alignment scenarios that can be encountered at organic heterojunctions is finally given. These results will help focus future efforts on developing functional organic interfaces for superior device performance.
This work was published under the
license
in:
M. Oehzelt, K. Akaike, N. Koch, G. Heimel:
Science Advances 1, e1501127 (2015).
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