A NIR phosphor with ultra-broadband emission enabled by dual energy transfer within two Cr emitters and Cr → Yb

Broadband near-infrared phosphors have received unprecedented attention in areas such as non-destructive food testing, plant growth light sources, night vision lighting, and medical diagnostics. It is challenging to design phosphors with significant full-width at half-maximum (FWHM) width variations. In this work, Sr 3 SiAl 10 O 20 :Cr 3+ (SSAO:Cr 3+ ) has two emission centers and achieves an interesting change of emission peaks from the ultra-narrow band (FWHM = 37 nm) to ultra-wideband (FWHM = 225 nm) with increasing Cr 3+ doping concentration. Photoluminescence decay lifetime fitting confirms the existence of energy transfer in two emission centers. The emission intensity and thermal stability of the phosphor after 950 nm were extended by introducing Yb 3+ ions. A NIR phosphor-converted LED was fabricated using SSAO:Cr 3+ ,Yb 3+ and a 410 nm LED chip, which shows great potential in the fields of night vision illumination, non-destructive monitoring, and information encryption. The NIR phosphor Sr 3 SiAl 10 O 20 , which realizes ultra-broadband emission via dual energy transfer within two Cr 3+ emitters and Cr 3+ → Yb 3+ , can be used for NIR pc-LEDs, showing great potential in the fields of night-vision illumination, nondestructive surveillance, and information encryption.