Optical and EPR studies of irradiated silicon dioxide materials

Optical absorption, luminescence, and electron spin resonance have been measured for crystalline and amorphous silicon dioxide materials. The luminescence data and its correlation with the optical absorption and spin resonance form basically new areas of research. For fast neutron irradiation the luminescence increases with irradiation, and a band tentatively identified with the oxygen vacancy correlates with the optical absorption and spin resonance for this defect. Above 10 to the 20th power neutrons/sq cm the luminescence, especially the oxygen vacancy luminescence, decreases, suggesting the formation of a large number of nonluminescent competing traps. Gamma irradiation has a much larger effect on amorphous silicon dioxide than on crystalline materials. The same effect seems to be present in gamma irradiated metal-oxide semiconductors up through 10 to the 7th power.