resumo
A general nonaqueous route has been applied for the preparation of rare-earth ordered nanocrystalline hybrid structures. In a simple one-pot reaction process, Y(3+) and Gd(3+) isopropoxides were reacted in an autoclave with 4-biphenyl methanol at 275 degrees C. This approach leads to crystalline rare-earth oxide thin layers (similar to 0.6 nm) regularly separated from each other by organic layers of biphenolate molecules. The optical properties of these hybrid materials doped with Eu(3+) and Nd(3+), which are optical active lanthanides ions emitting in the red and near infrared, respectively, are presented. They show significant advantages compared to standard phosphors, such as higher radiance and luminance values, the possibility to tune the emission chromaticity by varying the excitation wavelength, and a much larger excitation range (250-350 nm and 300-500 nm for the Eu(3+) and Nd(3+) doped nanohybrids, respectively) shifted toward the red.
palavras-chave
ORGANIC-INORGANIC NANOCOMPOSITES; BETA-DIKETONATE COMPLEX; NONAQUEOUS SYNTHESIS; OPTICAL-PROPERTIES; NMR; NANOPARTICLES; NANOCRYSTALS; CRYSTALLINE; NANOHYBRIDS; SOLUBILITY
categoria
Chemistry; Science & Technology - Other Topics; Materials Science
autores
Karmaoui, M; Mafra, L; Ferreira, RAS; Rocha, J; Carlos, LD; Pinna, N
nossos autores
João Rocha
Prof. Catedrático
Luís Carlos
Professor Catedrático
Luís Mafra
Investigador Principal
Maria Rute de Amorim e Sá Ferreira André
Professor Catedrático
Mohamed Karmaoui
Bolseiro de pós-Doutoramento