Boosting broadband short-wave infrared emission to achieve near-unity quantum efficiency via bridging Cr 3+ -Ni 2+ in spinel solid-solutions towards light-emitting diode applications.

Recently, short-wave infrared (SWIR) phosphor-converted light-emitting diodes (pc-LEDs) have garnered increased attention due to their widespread applications in night vision, biological imaging, and non-destructive testing. Nevertheless, the currently used SWIR phosphors suffer from poor thermal stability and low quantum efficiency. In this study, a finely tuned spinel-based solid solution, Mg 0.5 Zn 0.5 Ga 2 O 4 , is prepared to host Ni 2+ to induce SWIR emission. Cr 3+ is codoped as a sensitizer to bridge Cr 3+ and Ni 2+ ions, significantly enhancing blue light absorption and facilitating energy transfer (ET) to Ni 2+ ions. The champion SWIR phosphor exhibits a broadband emission centered at 1304 nm with a full width at half maximum (FWHM) of 250 nm, achieving a near-unity internal quantum efficiency (IQE = 97.7%) and a good thermal stability (70.7%@423 K). The fabricated SWIR pc-LED device delivers a high SWIR output power of 39.9 mW at 360 mA, enabling its application in non-destructive imaging and testing.