Ultra-broadband near infrared phosphor with wide spectral range and long peak wavelength achieved by double-site occupation

The miniaturization and intelligence of near infrared (NIR) devices urgently require an excellent broadband NIR phosphor. However, emission spectra of most NIR phosphors cover less than 1200 nm with a full width at half maximum (FWHM) less than 200 nm and a peak wavelength less than 900 nm. Here, we successfully developed ultra-broadband NIR phosphors ScNbO4:Cr3+ which can overcome the above shortcomings based on a double-site occupancy strategy. The phosphors achieve ultra-broadband NIR emission from 800 to 1400 nm with a peak wavelength at 980 nm. Its FWHM is up to 217 nm. The valence state of Cr ions in phosphors was analyzed. The double-site occupancy of Cr3+ ions in the host and the relationship between host structure and optical properties are discussed in detail. NIR light transmission experiments show that phosphors have potential application value in non-destructive analysis. This work develops an excellent NIR luminescent material and provides an efficient method to obtain ultra-broadband NIR phosphors with longer peak wavelength.