Near‐Infrared Broadband Emission for High Electroluminescence Efficiency by Cr3+/In3+‐Doped Germanate Phosphors

Abstract In this paper, a series of KGaGeO4:0.01Cr 3+ , xIn 3+ (KGGO:0.01Cr 3+ , xIn 3+ , x=0~0.08) phosphors were synthesized by high temperature method. KGGO:0.01Cr 3+ has a far red emission in the range of 600~900 nm ascribing to the 4T2→4 A2 spin‐allowed transition of Cr 3+ . With the incorporation of In 3+ , KGGO:Cr 3+ , In 3+ shows a near‐infrared (NIR) broadband emission in the range of 700~1200 nm, with red shift of the emission peak by 136 nm, and FWHM of 185 nm. The electroluminescence efficiency of NIR pc‐LED prepared by KGGO:0.01Cr 3+ , 0.02In 3+ is as high as 19 % under the output power of 25 mW, which can be applied in the night vision technology and microbial growth.