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

Abstract

In this paper, a series of KGaGeO4:0.01Cr³⁺, xIn³⁺ (KGGO:0.01Cr³⁺, xIn³⁺, x=0~0.08) phosphors were synthesized by high temperature method. KGGO:0.01Cr³⁺ has a far red emission in the range of 600~900 nm ascribing to the 4T2→4 A2 spin-allowed transition of Cr³⁺. With the incorporation of In³⁺, KGGO:Cr³⁺, In³⁺ 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:0.01Cr³⁺, 0.02In³⁺ is as high as 19 % under the output power of 25 mW, which can be applied in the night vision technology and microbial growth.