Optical absorption and electron paramagnetic resonance of the E’_alfa center in amorphous silicon dioxide

摘要

We report a combined study by optical absorption #1;OA#2; and electron paramagnetic resonance #1;EPR#2; spectroscopyon the E#1; #1; point defect in amorphous silicon dioxide #1;a-SiO2#2;. This defect has been studied in #2;-rayirradiated and thermally treated oxygen-deficient a-SiO2 materials. Our results have pointed out that the E#1; #1;center is responsible for an OA Gaussian band peaked at #3;5.8 eV and having a full width at half maximum of#3;0.6 eV. The estimated oscillator strength of the related electronic transition is #3;0.14. Furthermore, we havefound that this OA band is quite similar to that of the E#3; #1; center induced in the same materials, indicating thatthe related electronic transitions involve states highly localized on a structure common to both defects: theOwSi· moiety.