Highly Efficient Near-IR Photoluminescence of Er ³⁺ Immobilized in Mesoporous SBA-15

SiO ₂ mesoporous molecular sieve SBA-15 with the incorporation of erbium ions is studied as a novel type of nanoscopic composite photoluminescent material in this paper. To enhance the photoluminescence efficiency, two schemes have been used for the incorporation of Er ³⁺ where (1) Er ³⁺ is ligated with bis-(perfluoromethylsulfonyl)-aminate (PMS) forming Er(PMS) _x-SBA-15 and (2) Yb ³⁺ is codoped with Er ³⁺ forming Yb-Er-SBA-15. As high as 11. 17 × 10 ^-21cm ² of fluorescent cross section at 1534 nm and 88 nm of "effective bandwidth" have been gained. It is a 29.3% boost in fluorescent cross section compared to what has been obtained in conventional silica. The upconversion coefficient in Yb-Er-SBA-15 is relatively small compared to that in other ordinary glass hosts. The increased fluorescent cross section and lowered upconversion coefficient could benefit for the high-gain optical amplifier. Finally, the Judd-Ofelt theory has also been used for the analyses of the optical spectra of Er(PMS) _x-SBA-15.