Novel broadband near-infrared emitting phosphor LiGe2(PO4)3:Cr3+ with tuning and enhancement of NIR emission by codoping Sb5+

Abstract

A highly efficient novel broadband NIR emission peaking at 814 nm with a large full width at half maximum (FWHM) of 170 nm was realized in novel LiGe2(PO4)3:Cr3+ (LGP:Cr3+) with internal quantum efficiency about 90% (IQE). An innovative strategy of Sb5+ codoped phosphor (LGP:Cr3+,Sb5+) led to the increases in the luminescence intensity and thermal stability. Moreover, tunable NIR emission from 814 to 743 nm was achieved which can be ascribed to the attenuation of electron-phonon coupling with increasing Sb5+-concentration. The output powers of phosphor-converted lighting emitting diodes (pc-LEDs) by combining 460 nm chips with LGP:0.01Cr3+ and LGP:0.05Cr3+,0.05Sb5+ phosphors reached 34.68 mW @ 300 mA and 40.36 mW @ 250 mA, respectively. Our results prove that the codoped strategy can provides a new idea for research on tunable NIR phosphors.