Regensburg 2007 – wissenschaftliches Programm

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HL: Fachverband Halbleiterphysik

HL 13: Poster 1

HL 13.76: Poster

Montag, 26. März 2007, 15:00–17:30, Poster A

In situ spectroscopy and characterisation of organic solar cells — •F. Holch, J. Pernpeintner, A. Schöll, and E. Umbach — Universität Würzburg, Experimentelle Physik II, 97074 Würzburg

Electronic devices based on organic semiconductors belong to a field of growing interest in fundamental and application related research. The different experimental methods and preparation techniques often complicate a comprehensive understanding of fundamental properties and their impact on device performance. We present first results from a new project focussing on organic solar cells using relatively small organic molecules. For a better understanding of the limiting parameters basic questions such as the determination of energy levels in the active layer as well as the bandoffsets/–alignment at the organic hetero–interface and contacts will be addressed using photoelectron spectroscopy (UPS) and inverse photoelectron spectroscopy (IPES). In situ electrical measurements (IV) help to associate fundamental results with device characteristics such as efficiency and fill factor. In order to avoid uncontrolled contamination, the complete fabrication (active layer and contacts) and characterisation is performed under clean and well defined conditions in UHV. As a benefit of this approach the influence of contamination occurring, e.g., during the fabrication process or device operation can be analysed systematically. Moreover, metal deposition methods are optimised in order to reduce damage to the sensitive organic layer. The interplay between interface morphology and interaction will be investigated by XPS using a peeling technique, which has already been successfully applied to Au/DIP contacts.