| Texto completo | |
| Autor(es): |
Macedo, Wagner Costa
;
Bispo Junior, Airton Germano
;
Rocha, Kleper de Oliveira
;
de Souza Albas, Agda Eunice
;
Pires, Ana Maria
;
Teixeira, Silvio Rainho
;
Longo, Elson
Número total de Autores: 7
|
| Tipo de documento: | Artigo Científico |
| Fonte: | MATERIALS TODAY COMMUNICATIONS; v. 24, p. 8-pg., 2020-09-01. |
| Resumo | |
Eu-doped 1, 3 and 5 % CaZrO3 red-emitting phosphors were synthesized for the first time using the microwave-assisted hydrothermal method followed by heat treatment at 1200 degrees C. After the crystallization, the orthorhombic CaZrO3 and the non-stoichiometric cubic Ca0.15Zr0.85O1.85 phases were identified for all samples, and the portion of the non-stoichiometric phase increases as the Eu3+ concentration increases. The excitation spectra of the phosphors display Eu3+ f-f excitation bands (namely at 395 nm and 464 nm) and the Eu3+ -> O-2 charge transfer band at 250 nm, confirming that the CaZrO3 host acts as sensitizer for the Eu3+ luminescence. Likewise, the emission spectra feature the typical Eu3+ emission within the red spectral region, displaying CIE color coordinates of (0.642; 0.332), (0.663; 0.330) and (0.668; 0.327) for the 1, 3 and 5 % doped samples, respectively, indicating high emission color purity. By using Eu3+ as spectroscopic probe, the high-resolution selective emission spectra (14 K) confirm that Eu3+ replaces Ca2+ and Zr4+ local sites in both CaZrO3 and the Ca0.15Zr0.85O1.85 phases. Finally, the high absolute emission quantum yield of the 3 %-doped phosphor found at 393 nm (0.29 +/- 0.03) confirms its potential application as red-emitting phosphor, especially in rapid identification of latent fingerprints, security ink or as red-emitting coating of near-UV LEDs for WLED applications. (AU) | |
| Processo FAPESP: | 16/20421-9 - Dispositivos tricromáticos a base de Ba2SiO4:Eu3+ e/ou Tb3+: síntese sol-gel e deposição eletroforética visando aplicação em LEDs brancos |
| Beneficiário: | Airton Germano Bispo Júnior |
| Modalidade de apoio: | Bolsas no Brasil - Doutorado Direto |
| Processo FAPESP: | 13/07296-2 - CDMF - Centro de Desenvolvimento de Materiais Funcionais |
| Beneficiário: | Elson Longo da Silva |
| Modalidade de apoio: | Auxílio à Pesquisa - Centros de Pesquisa, Inovação e Difusão - CEPIDs |
| Processo FAPESP: | 17/21995-1 - Dispositivos tricromáticos a base de Ba2SiO4:Eu3+ e/ou Tb3+: síntese sol-gel e deposição eletroforética visando aplicação em LEDs brancos |
| Beneficiário: | Airton Germano Bispo Júnior |
| Modalidade de apoio: | Bolsas no Exterior - Estágio de Pesquisa - Doutorado Direto |