Structural instability of Si-nanocrystals in a (SiH2)n matrix

We study thin films made by reactive sputtering of Si with hydrogen and deposited on liquid-N 2 cooled substrates. At room-temperature such films show broad luminescence in the visible region of the spectrum. They contain small Si crystallites in a (SiH 2 ) n matrix. We observe the structural changes in these films when subjected to thermal treatment and under UV light. Raman scattering, infrared absorption and thermal effusion of hydrogen are used to characterize the film properties.