| AVS 66th International Symposium & Exhibition | |
| Spectroscopic Ellipsometry Focus Topic | Wednesday Sessions |
| Session EL+AS+EM+TF-WeM |
| Session: | Optical Characterization of Thin Films and Nanostructures |
| Presenter: | Yanzeng Li, University of North Carolina at Charlotte |
| Authors: | Y. Li, University of North Carolina at Charlotte M. Kocherga, University of North Carolina at Charlotte S. Park, University of North Carolina at Charlotte M. Lata, University of North Carolina at Charlotte M.J. McLamb, University of North Carolina at Charlotte G.D. Boreman, University of North Carolina at Charlotte T.A. Schmedake, University of North Carolina at Charlotte T. Hofmann, University of North Carolina at Charlotte |
| Correspondent: | Click to Email |
Tang and VanSlyke demonstrated light emission from the first practical electroluminescent device based on a double-organic-layer structure of tris(8-hydroxyquinoline)aluminum, Alq3, and a diamine film in the late 80's. Since then, organic light emitting diodes (OLED) based on metal chelates such as Alq3 have been widely studied. Despite the widespread use of Alq3, there has been a broad search for new materials with improved properties, in particular, with respect to their chemical and electrochemical stability. We have recently reported on the successful synthesis of a neutral, hexacoordinate silicon-based fluorescent complex Si(bzimpy)2. Our results indicate that Si(bzimpy)2 exhibits inherent advantages such as the tunability of the luminescence in the visible spectrum, greater thermal stability, and high charge mobility that is comparable to that of Alq3. Despite the successful synthesis and encouraging electroluminescence at 560 nm the complex dielectric function of the water stable complex has not been reported yet. Here we present spectroscopic ellipsometry data which were obtained from a Si(bzimpy)2 thin-film in the spectral range from 300~nm to 1900~nm. A parameterized model dielectric function composed of a Tauc-Lorentz and Gaussian oscillators is employed to analyze the experimental ellipsometry data. We find a good agreement between the critical point energies observed experimentally and our density functional theory calculations reported recently.