CATHODOLUMINESCENCE MICROCHARACTERIZATION OF THE DEFECT STRUCTURE OF QUARTZ

Cathodoluminescence (CL) spectroscopy has been used to investigate the irradiation-sensitive defect structure of ultrapure synthetic quartz at 295 and 80 K. CL emissions are identified with particular defect ce nters. Insight into the processes of defect formation and subsequent e lectromigration resulting from the trapped-charge-induced electric fie ld following irradiation by a stationary continuous electron beam are presented. The CL emissions are associated with either a nonbridging o xygen hole center (NBOHC) or trapped-electron Si-3(-) center (1.91 eV) ; NBOHC with OH precursor (1.95 eV); the radiative recombination of th e self-trapped exciton (STE) in irradiation-induced amorphous SiO2 out growths (2.28 eV); an extrinsic process (2.46 eV); the radiative recom bination of the STE associated with the E'(1) center in a-SiO2 (2.72 e V); an additional component at 80 K due to the radiative recombination of the STE associated with the E'(2) center (2.69 eV); an intrinsic p rocess (2.95 eV); and the charge-compensated substitutional aluminum c enter (3.12 eV).