Strong explosive interaction of hydrogenated porous silicon with oxygen at cryogenic temperatures.
We report new types of heterogeneous hydrogen-oxygen and silicon-oxygen branched chain reactions which have been found to proceed explosively after the filling of pores of hydrogen-terminated porous silicon (Si) by condensed or liquid oxygen in the temperature range of 4.2-90 K. Infrared vibrational absorption spectroscopy shows that, while initially Si nanocrystals assembling the layers have hydrogen-terminated surfaces, the final products of the reaction are SiO2 and H2O. Time-resolved optical experiments show that the explosive reaction develops in a time scale of 10(-6) s. We emphasize the remarkable structural properties of porous Si layers which are crucial for the strong explosive interaction.
Kovalev
D
D
Technische Universität München, Physik-Department E16, D-85747 Garching, Germany.
Timoshenko
V Y
VY
Künzner
N
N
Gross
E
E
Koch
F
F