OXYGEN DEFECT CENTER RED ROOM-TEMPERATURE PHOTOLUMINESCENCE FROM FRESHLY ETCHED AND OXIDIZED POROUS SILICON

Electron spin resonance and photoluminescence experiments have been pe rformed on freshly etched and oxidized porous silicon. Results indicat e the presence of oxygen-related centers (nonbridging oxygen-hole cent er clusters), which consist of similar core structures in as-made and oxidized porous silicon (PSi) samples. A direct correlation exists bet ween the presence of these centers and a red photoluminescence observe d in both freshly anodized and oxidized PSi, suggesting that this emis sion process is the result of optical transitions in the oxygen-hole c enters.