Hydrothermal synthesis of amorphous SiO2 nanoblades and their photoluminescence properties

Large-scale amorphous SiO₂ nanoblades with typical widths of 300-600 nm, thickness of a few tens of nm, and lengths up to 12 ¿m have been synthesized on a silicon substrate covered with a 100-nm-thick crystalline SiO₂ buffer layer in a controlled aqueous solution. Intense blue luminescence centered at 3.0 and 2.8 eV was observed in the as-synthesized SiO₂ nanoblades. The 2.8-eV band can be attributed to the paramagnetic E´ defects and/or the neutral oxygen-vacancy defects, and the 3.0-eV band may be due to the H-complexed oxygen vacancies, twofold coordinated silicon centers, and/or weak O-O bonds.