Dynamics of photosensitized formation of singlet oxygen by porous silicon in aqueous solution
- Department of Electrical and Electronics Engineering, Faculty of Engineering, Kobe University, Rokkodai, Nada, Kobe 657-8501 (Japan)
Generation of singlet oxygen due to energy transfer from photoexcited silicon nanocrystals in D{sub 2}O is demonstrated. It is shown that the singlet oxygen generation efficiency, i.e., the intensity of near-infrared emission from singlet oxygen gradually decreases when Si nanocrystals are continuously irradiated in O{sub 2}-saturated D{sub 2}O. The mechanism of the photodegradation of the photosensitizing efficiency is studied using photoluminescence and infrared absorption techniques. Experimental results suggest that the interaction of photogenerated singlet oxygen with the hydrogen-terminated surface of silicon nanocrystals results in photo-oxidation of silicon nanocrystals, and the surface oxides reduce the photosensitizing efficiency. It is also demonstrated that photo-oxidation of porous silicon in O{sub 2}-saturated water results in a strong enhancement of the photoluminescence quantum yield of porous Si.
- OSTI ID:
- 20884945
- Journal Information:
- Journal of Applied Physics, Vol. 100, Issue 12; Other Information: DOI: 10.1063/1.2402343; (c) 2006 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA); ISSN 0021-8979
- Country of Publication:
- United States
- Language:
- English
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