Spectroscopic studies of Cu~(2+) ions in sol-gel derived silica matrix

摘要

The Cu~(2+) ion doped silica gel matrices in monolithic shape were prepared by hydrolysis and condensation of tetraethyl orthosilicate (TEOS). The absorption, transmittance and fluorescence spectra of the gel matrices heat treated at different temperatures were monitored. The loss of water and hydroxyl group from silica network changes the optical properties of the Cu~(2+) ions in the host, noted by the change in colour of monolith and spectral characteristics. The pronounced blue shift observed (700-900 nm to 600-850 nm) for the broad band of the absorption spectra of the samples heated up to 700 deg C is attributed to the ligand field splitting and partial removal of hydroxyl group from the silica matrices. The results indicated broadband filtering effects of the samples in the wavelength region 400-600 nm. Absorption and fluorescence spectra of the glass matrices heated to 1000 deg C confirms the conversion of Cu~(2+) ion to Cu~+ ion.