Highly mobile oxygen hole-type charge carriers in fused silica

Some peculiar positive charge carriers are thermally generated in fused silica above 500 C. These charge carriers appear to be positive holes, chemically O-states, probably arising from dissociation of peroxy defects. The charge carriers give rise to a pronounced positive surface charge which disappears upon cooling but can be quenched by rapid quenching from about 800 C. Reheating to 200 C remobilizes these charge carriers and causes them to anneal below 400 C. The generation of positive holes charge carriers may be important to understand failure mechanisms of SiO2 insulators.