High‐Efficiency Short‐Wave Infrared Emitter Enabled by Cr3+–Yb3+ Co‐Doped Phosphor

Abstract The utilization of phosphor‐converted light‐emitting diodes (pc‐LEDs) as compact short‐wave infrared (SWIR) emitters has emerged as a promising strategy for miniature SWIR spectrometers in portable devices, enabling diverse applications such as nondestructive identification, bioimaging, night‐vision surveillance, and optical communication. However, discovering phosphors capable of efficiently absorbing blue light and emitting pure SWIR light (>900 nm) remains a significant challenge. Here, highly efficient and thermally stable SWIR luminescence of Yb 3+ upon blue LED excitation by employing Cr 3+ –Yb 3+ energy transfer in Y 3 Ga 5 O 12 garnet is reported. The prepared Y 3 Ga 5 O 12 :Cr 3+ ,Yb 3+ phosphor exhibits intense SWIR emission spanning from 900 to 1150 nm at 438 nm excitation, coupled with ultra‐high internal/external quantum efficiency of 80.8%/40.2% and excellent luminescence thermal stability (108%@150 °C). A SWIR pc‐LED prototype fabricated by incorporating the optimized phosphor with a commercial 450 nm blue LED chip, shows exceptional SWIR luminescence performance, delivering a SWIR output power of 92.7 mW at a driving current of 350 mA and a photoelectric efficiency of 21.5% at 10 mA. This work opens up a new avenue for designing SWIR phosphors that exhibit efficient and thermally stable photoluminescence with blue LED excitation, demonstrating significant potential for next‐generation high‐power compact SWIR light sources.