Characteristic red photoluminescence band in oxygen-deficient silica glass

We studied a red photoluminescence (PL) band at about 1.8 eV with full widt h at half maximum of 0.2-0.4 eV in a series of oxygen deficient-type silica s before and after gamma irradiation. The decay lifetime of the PL was esti mated to be about 200 ns. The PL excitation peak was found to be located at 2.1 eV. The intensity of the 1.8 eV band was enhanced by about 100 times a fter gamma irradiation up to a dose of 10 MGy. These results suggest that t he 1.8 eV PL is associated with oxygen deficient states in silica glass, wh ich were introduced during manufacture and were enhanced further by the gam ma irradiation. Comparison of the PL properties was made with other lumines cent Si-based materials in terms of the peak energy, lifetime, and temperat ure dependence. (C) 1999 American Institute of Physics. [S0021-8979(99)0801 3-5].