Full-color phosphors from amine-functionalized crosslinked hybrids lacking metal activator ions
Nenhuma Miniatura disponível
Data
2001-04-01
Autores
Carlos, Luís D.
Sá Ferreira, Rute A.
De Zea Bermudez, Verónica
Ribeiro, Sidney José Lima [UNESP]
Título da Revista
ISSN da Revista
Título de Volume
Editor
Resumo
Sol-gel derived hybrids that contain OCH2CH2 (polyethylene glycol, PEG) repeat units grafted onto a siliceous backbone by urea, -NHC(=O)NH-, or urethane, -NHC(=O)O-, bridges have been prepared. It is demonstrated that the white light PL of these materials results from an unusual convolution of a longer lived emission that originates in the NH groups of the urea/urethane bridges with shorter lived electron-hole recombinations occurring in the nanometer-sized siliceous domains. The PL efficiencies reported here (maximum quantum yields at room temperature of ≈ 0.20 ± 0.02 at a 400 nm excitation wavelength) are in the same range as those for tetramethoxysilane-formic acid, and APTES-acetic acid, sol-gel derived phosphors. The high quantum yields combined with the possibility of tuning the emission to colors across the chromaticity diagram present a wide range of potential applications for these hybrid materials.
Descrição
Palavras-chave
Amines, Crosslinking, Electrons, Grafting (chemical), Molecular weight, Organic acids, Photoluminescence, Polyethylene glycols, Quantum theory, Sol-gels, Urea, Chromaticity, Electron-hole recombination, Formic acid, Quantum yield, Tetramethoxysilane, Urethane, Phosphors
Como citar
Advanced Funtional Materials, v. 11, n. 2, p. 111-115, 2001.