resumo
The -substituted -diketonate [Ln(3Cl-acac)(3)(H2O)(2)] [Ln=Tb, Gd] complexes (with 3Cl-acac(-) being 3-chloro-2,4-pentanedionate) were characterized by elemental analysis, infrared, ultraviolet (UV)-visible and photoluminescence spectroscopies. For comparison purposes regarding photoluminescence, the well-known [Tb(acac)(3)(H2O)(2)] complex was also synthesized. By considering the phosphorescence spectra of [Gd(3Cl-acac)(3)(H2O)(2)], the effect of chloride replacement of hydrogen on the triplet state energy of the 3Cl-acac ligand was revealed. To support the interpretation and rationalization of the experimental results, Time-dependent DFT calculations were performed on Tb(3Cl-acac)(3)(H2O)(2). Additionally, the possibility of Tb(3Cl-acac)(3)(H2O)(2) to be used as potential green-emitting phosphor material for solid-sate light emitting diodes was evaluated. A prototype was successfully fabricated coating a near-UV LED (370nm) with the Tb(3Cl-acac)(3)(H2O)(2) complex.
palavras-chave
RARE-EARTH; ENERGY-TRANSFER; QUANTUM YIELD; LUMINESCENCE; COMPLEX; PHOSPHORS; DENSITY; LIGAND; DIPHENYLETHYNE; TERBIUM(III)
categoria
Chemistry
autores
Nolasco, MM; Vaz, PM; Vaz, PD; Ferreira, RAS; Lima, PP; Carlos, LD
nossos autores
Luís Carlos
Professor Catedrático
Maria Rute de Amorim e Sá Ferreira André
Professor Catedrático
Mariela Martins Nolasco
Investigador Auxiliar
Patrícia Vaz
Estudante de doutoramento
Patrícia Pereira Lima
Bolseiro de pós-DoutoramentoGrupos
G2 - Materiais Fotónicos, Eletrónicos e Magnéticos
G6 - Materiais Virtuais e Inteligência Artificial
agradecimentos
We would like to thank Fundacao para a Ciencia e a Tecnologia (FCT), the European Union, QREN, FEDER through Programa Operacional Factores de Competitividade (COM-PETE) and Laboratorio Associado Centro de Investigacao em Materiais Ceramicos e Compositos, CICECO (FCOMP-01-0124-FEDER-037271 - Ref. FCT PEst-C/CTM/LA0011/2013), for their general funding scheme. MMN (BPD/UI96/3340/2014) and PPL (BPD/UI96/5458/2014) also acknowledge the post-doctoral scholarships under the Project Mais Centro - PORC, CENTRO-07-ST24-FEDER-002032.