Efficient Broadband Short‐Wave Infrared Luminescence at 1400 nm Enabled by Cr 3+ ‐Yb 3+ Energy Shuttle Design

ABSTRACT Broadband short‐wave infrared (SWIR) light sources are essential for advanced applications such as spectroscopy, optical communication, anti‐counterfeiting, and biological imaging. However, the advancement of SWIR emitters still faces significant challenges, including limited emission bandwidths, insufficient luminescence efficiency, and unsatisfactory device compatibility. Here, we report an efficient broadband SWIR‐emitting phosphor, Yb 3 Ga 5 O 12 :Cr 3+ , Ni 2+ , enabled by the Cr 3+– Yb 3+ energy shuttle design. The cooperative energy transfer from Cr 3+ to Yb 3+ and subsequently to Ni 2+ produces a broad emission spanning 900–1600 nm, with an intense Ni 2+ SWIR luminescence peaking at ∼1400 nm and high internal/external quantum efficiency of 43.1%/23.1%. Heavy doping of Cr 3+ (35%) yields optimum SWIR emission, suppressed non‐radiative losses, and a prolonged Ni 2+ lifetime (∼1.064 ms), confirming the efficient multi‐ion energy transfer pathway. The phosphor‐converted broadband SWIR LED prototype device by a combination of 450 nm blue LED and the optimized Yb 3 Ga 5 O 12 :35%Cr 3+ , 0.1%Ni 2+ phosphor is fabricated, delivering a maximum SWIR output power of ∼2.38 mW at 140 mA input current. Besides, the fabricated Yb 3 Ga 5 O 12 :Cr 3+ , Ni 2+ crystal fiber shows broadband SWIR luminescence upon 450 or 980 nm laser excitation, highlighting its potential for multi‐response fiber amplifiers in optical communication. This work provides a promising material platform for high‐performance SWIR emitters and photonic devices.