Effect of doping concentration on broadband near-infrared emission of Bi doped zeolites

A series of Bi doped zeolites are prepared by an ion-exchange process by changing doping concentration in a wide range, and the optical properties are investigated. The near-infrared photoluminescence (PL) intensity, full width at half maximum and decay time depend strongly on Bi doping concentration. The PL intensity increases 178 times when the concentration is changed from 0.3 to 1.5 at. %. At the same time, the lifetime increases from 83 to 527 μs. The results prove the model that doped Bi acts not only as optically active centers, but also as pore-sealing substances to isolate the centers. The comparison of PL and Raman data suggests that in addition to previously proposed Bi2O3, other Bi-related materials, probably Bi metal, play an important role to isolate the active centers.

Figure optionsDownload as PowerPoint slideHighlights
► A series of Bi doped zeolites are prepared by an ion-exchange process.
► The optical properties of Bi doped zeolites for different doping concentration.
► The PL, FWHM, and decay time depend strongly on doping concentration.
► Doped Bi ions act as optically active centers and pore-sealing substances.
► Bi2O3 and Bi metal play an important role to isolate the active centers.