Screening of Broadband Near-Infrared Cr³⁺-Activated Phosphors Using Ce³⁺ as a Probe

Abstract

Near-infrared phosphor-converted light-emitting diodes (NIR pc-LEDs) are ideal miniaturized NIR light sources, but it is still difficult to find broadband-emitting NIR phosphors due to the lack of appropriate material design principles. In this work, we propose a method to find hosts yielding broadband NIR Cr3+ emission by screening Ce3+-doped phosphor hosts for which both Ce3+ and Cr3+ can occupy the same crystallographic site. A NIR phosphor Ba3Sc4O9:Cr3+ (BSO:Cr3+) with an emission peak at 835 nm and a full width at half-maximum (FWHM) of 188 nm is obtained, where Ce3+ or Cr3+ is accommodated at the same Sc3+ site. The BSO:Cr3+ ceramic is demonstrated to produce a NIR emitter with an output power of 14.56 mW when driven by a blue laser diode at 5.0 V/100 mA. By following the proposed method, two broadband NIR phosphors composed of Li3Sc2(PO4)3:Cr3+ (λem = 1000 nm, FWHM = 223 nm) and Na3Sc2(PO4)3:Cr3+ (λem = 895 nm, FWHM = 184 nm) are further discovered.

Broadband emitting phosphor Sr6Sc2Al4O15:Cr3+ for near-infrared LEDs

“…† As addressed in our previous report, the CFS of Ce 3+ cannot be directly linked to that of Cr 3+ . 31 It is also true in this work. The luminescence of SSA:Ce 3+ shows a very broad emission band covering the range of 450-800 nm (Fig.…”

“…Similar to Cr 3+ , Ce 3+ also shows strong CFS-dependent luminescence, and its luminescence is redshifted as CFS increases. 28–30 In previous work, 31 we have realized that maybe the luminescence of Cr 3+ ions can be predicted by Ce 3+ due to their luminescence all being strongly dependent on CFS. Cr 3+ may exhibit broadband emission when it is accommodated into the same octahedron site at which Ce 3+ is located in a host.…”

Advancing Reporting Guidelines for Optimal Characterization of Inorganic Phosphors

“…When designing phosphor materials with transition metal ions as activators, such as Mn-based red/near-infrared phosphors, Cr-based infrared phosphors, Fe-based near-infrared phosphors, and Ni-based shortwave infrared phosphors, understanding the local structure is crucial for proposing new luminescence mechanisms. Electron paramagnetic resonance (EPR) in correlation with a superconducting quantum interference device (SQUID) is an effective approach for estimating the local structural features around the transition metal .…”

Highly efficient and thermally stable broadband near-infrared emitting garnet Ca3Sc2Ge3O12:Cr3+,Ce3+ phosphors for multiple pc-LED applications

“…25–27 In particular, Liu et al revealed the relationship between the crystal field intensities of Ce 3+ and Cr 3+ , that is, when Ce 3+ is located in a weak crystal field, the emission of Cr 3+ will also produce broadband emission due to its presence in the weak crystal field. 28 And the absorption bands of Cr 3+ doped NIR phosphors are mostly located in the blue-green light region, which means that Ce 3+ is an excellent sensitizer for Cr 3+ activated broadband NIR phosphors. Wu et al co-doped Ce 3+ into Ca 2 LuHf 2 Al 3 O 12 :Cr 3+ to increase the emission intensity of Cr 3+ by three times through energy transfer from Ce 3+ to Cr 3+ .…”