Photosensitized generation of singlet oxygen in porous silicon studied by simultaneous measurements of luminescence of nanocrystals and oxygen molecules

Journal Article · Fri Jul 01 00:00:00 EDT 2011 · Journal of Applied Physics

DOI:https://doi.org/10.1063/1.3586044· OSTI ID:22036654

Gongalsky, M B; Kharin, A Yu; Zagorodskikh, S A; Osminkina, L A; Timoshenko, V Yu ^[1]

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1. Faculty of Physics, M.V. Lomonosov Moscow State University, 1, Leninskie Gory, Moscow 119991 (Russian Federation)

Photosensitization of singlet oxygen generation in porous silicon (PSi) was investigated by simultaneous measurements of the photoluminescence (PL) of silicon nanocrystals (nc-Si) and the infrared emission of the {sup 1}{Delta}-state of oxygen molecules at 1270 nm (0.98 eV) at room temperature. Photodegradation of the nc-Si PL properties was found to correlate with the efficiency of singlet oxygen generation. The quantum efficiency of singlet oxygen generation in PSi was estimated to be about 1%, while the lifetime of singlet oxygen was about fifteen ms. The kinetics of nc-Si PL intensity under cw excitation undergoes a power law dependence with the exponent dependent on the photon energy of luminescence. The experimental results are explained with a model of photodegradation controlled by the diffusion of singlet oxygen molecules in a disordered structure of porous silicon.

• OSTI ID: 22036654
• Journal Information: Journal of Applied Physics, Vol. 110, Issue 1; Other Information: (c) 2011 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA); ISSN 0021-8979
• Country of Publication: United States
• Language: English

Related Subjects

75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
77 NANOSCIENCE AND NANOTECHNOLOGY
36 MATERIALS SCIENCE
CRYSTALS
DIFFUSION
DISSOCIATION
EV RANGE
EXCITATION
LASERS
LIFETIME
MOLECULES
NANOSTRUCTURES
OXYGEN
PHOTOLUMINESCENCE
PHOTOLYSIS
PHOTONS
POROUS MATERIALS
QUANTUM EFFICIENCY
SEMICONDUCTOR MATERIALS
SILICON
TEMPERATURE RANGE 0273-0400 K
THIN FILMS