SIO2-GE PHOTOLUMINESCENCE - DETAILED MAPPING OF THE EXCITATION-EMISSION UV PATTERN

Photoluminescence (PL) data on SiO2:Ge samples have been obtained at 9 and 300 K by synchrotron radiation excitation, achieving a detailed m apping of the emission/excitation pattern in the UV and VUV energy ran ge. Emission/excitation PL data have been analyzed by means of two-var iables Gaussian components. New PL features have been identified, clar ifying the composite nature of the excitation structure. The analysis of the high-energy portion of the collected spectra confirms that the alpha and beta emissions possess several excitation channels. The over all pattern calls for at least three distinct types of PL centers to j ustify the observed PL components: at about 3.1 and 4.3 eV (excited at 7.3, 6.6, and 5.4 eV), at 4.4 eV (excited at 5.1 eV), and 2.9 and 3.9 eV (excited at about 7.0 and 4.7 eV). [S0163-1829(98)03304-9].