Berlin 2008 – wissenschaftliches Programm

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MM: Fachverband Metall- und Materialphysik

MM 23: Poster session

MM 23.38: Poster

Dienstag, 26. Februar 2008, 14:45–18:00, Poster B

Charge separation between type II aligned closed packed CdTe and CdSe nanocrystals — •Dieter Groß, Andrei S. Susha, Thomas A. Klar, Andrey L. Rogach, and Jochen Feldmann — Photonics and Optoelectronics Group, Physics Department and CeNS, Ludwig-Maximilians-Universität München, Germany

Combinations of CdTe and CdSe provide type II structures with the lowest excited energy state for electrons in CdSe and the lowest excited hole state in CdTe. This kind of energy level alignment facilitates the separation of photo-excited charge carriers in modern thin film solar cells. We have observed an efficient photoluminescence quenching and a reduced life time of the CdTe nanocrystal emission in hybrid structures made of colloidal CdTe and CdSe nanocrystals. These effects have been observed in both, layered structures created by a layer-by-layer technique and clustered assemblies in solution, providing both a controlled assembly with a short inter-particle distance (< 1 nm). We interpret this suppression of the CdTe emission to be due to spatial charge separation of the photo-excited electron-hole pairs.