Broadband near-infrared luminescence from Fe 3+ -activated NaScSi 2 O 6 phosphors for luminescence thermometry and night-vision applications.

Broadband near-infrared (NIR) materials have recently evoked considerable interest for versatile applications, but the choices of efficient emitters for NIR phosphors are rather limited. Herein, an Fe 3+ -activated NaScSi 2 O 6 phosphor has been successfully synthesized by a solid-state reaction method. A broad NIR emission band is observed at 900 nm when excited at 300 nm ultraviolet light, reaching a full-width at half maximum (FWHM) of 135 nm and an internal quantum efficiency (IQE) of 13.3%. The luminescence is related to 3d-3d transitions of Fe 3+ in the octahedral site, and verifies the effectiveness of the Fe 3+ activator in realizing efficient NIR emission. The emission intensity of Fe 3+ ions shows a linear quenching tendency in the temperature range of 293-433 K. The feasibility of the as-synthesized phosphors in applications such as NIR luminescence thermometry and NIR patches was also investigated.