Highly Photoluminescent Sulfide Clusters Confined in Zeolites

• Tipo: Artigo em Revista Científica Internacional
• Data: 2018

Autores

Ruivo, A (Autor) Outra; Coutino Gonzalez, E (Autor) Outra; Santos, MM (Autor) FCUP; Baekelant, W (Autor) Outra; Fron, E (Autor) Outra; Roeffaers, MBJ (Autor) Outra; Pina, F (Autor) Outra; Hofkens, J (Autor) Outra; Laia, CAT (Autor) Outra

Revista

Título: Journal of Physical Chemistry C

Vol. 122

ISSN: 1932-7447

Editora: American Chemical Society

Indexação

ISI Web of Knowledge - 9 Citações

Outras Informações

ID Authenticus: P-00P-08S

DOI: 10.1021/acs.jpcc.8b01247

Abstract (EN): The design, synthesis and photoluminescence characterization of sulfide cluster-based zeolitic materials with the general formula Na-8[SiAlO4](6)SxCl2-2x is presented in this report. The employed experimental conditions, which included the thermal treatment of sodium Linde type A (Na-LTA) zeolites in the presence of Na2SO4 and NaCl, yielded highly photoluminescent sulfur-zeolites with remarkably large Stokes shifts. An emission band at 650 nm for samples with low sulfur contents is observed when excited at 380 nm, which is fully consistent with S-2(-) clusters as light-emitting centers. These orange emitting materials display external quantum efficiencies (EQEs) reaching 53% with peculiar high temperature photoluminescence stability up to 450 degrees C. For higher S/Cl molar ratios, a gradual conversion to near-infrared (NIR) light-emitting centers is observed with a maximum at 780 nm. This novel NIR luminescent species with EQEs of about 10% are attributed to polysulfide clusters (tentatively S-4(2-) species). Given the high EQE values, large Stokes shifts, and thermal stability, the materials presented in this report can find applications in light down-conversion systems or as phosphors in lighting devices.

Idioma: Inglês

Tipo (Avaliação Docente): Científica

Nº de páginas: 10