We report the spectroscopic characterization in air andin vacuum atmosphere of the visible luminescence relatedto silica surface defects. Time resolved photoluminescencetechnique allows to discern two contribution: the first one,observed both in air and in vacuum, is the well known blueband, peaked around 2.8 eV decaying in τ~5 ns; the second,only observed in vacuum, is a structured emission in theviolet range characterized by two vibronic progressionsspaced 1370 cm-1 and 360 cm-1 decaying in τ~90 ns. On thebasis of these spectroscopic properties, we revise thestructural models of luminescent defects.
|Number of pages||2|
|Publication status||Published - 2014|