An ultra broadband NIR phosphor LiScSnO4:Cr3+ with emission wavelength peaking at 900 nm for component analysis

Abstract

Near-infrared phosphor conversion light-emitting diode (NIR pc-LED) is a widely used ideal NIR light source due to its unique advantages of low cost, energy saving, compactness and long operational lifetime. However, there is currently a scarcity of appropriate phosphor for NIR light sources utilized in spectral detection, with emission peak larger than 850 nm and steady spectrum output of ultra broadband spectra. Here, a broadband Cr3+ activated LiScSnO4 (LSS) phosphor (λex-max = 460 nm) matching the pump band of commercial blue LED chips has been developed, which shows a long wavelength NIR emission peaking at 900 nm. Cr3+ simultaneously replace the Wyckoff site co-occupied by Sc and Sn in LSS. Due to the difference of local environment of the specific crystal field, two different wide emission bands are caused. These two broad emission bands both contribute to the broadband luminescence with a full width at half maximum (FWHM) of 227 nm. Benefiting from the crystallography consistent Wyckoff position occupation of Cr3+ ions, the spectral distribution of LSS:Cr3+ exhibit excellent stability over a wide temperature span (80–423 K). The broadband NIR pc-LED prototype based on LSS:Cr3+ shows great potential in NIR spectrum detection, night vision imaging applications.