The generation of the Si dangling bond defect in amorphous SiO2 (E' centre), as

produced by tunable pulsed UV laser radiation, was investigated using in situ

optical absorption measurements. The defect generation efficiency peaked when

the photon energy equalled ~5.1eV. It depended quadratically upon the laserintensity

and was related to the native linear absorption due to Ge impurities. A

model was proposed in which the generation of E' was assisted by a two-step

absorption process occurring on Ge impurity sites.

Generation of Defects in Amorphous SiO2 Assisted by Two-Step Absorption on

Impurity Sites. F.Messina, M.Cannas, R.Boscaino: Journal of Physics - Condensed

Matter, 2008, 20[27], 275210