Engineering the local structure of ZnGa2O4: Cr3+ via Mg substitution to realize superior luminescence

Recently, near-infrared (NIR) light-emitting diodes (LED) have attracted much research attention globally. To advance this technology, NIR phosphors with high efficiency, thermal stability, and broad bands are required. In this work, we modified ZnGa 2 O4:Cr 3+ phosphor with Mg 2+ ions. Results show that this method improves the luminescence intensity of ZnGa 2 O4:Cr 3+ phosphor, and the emission wavelength of the sample can be changed by doping different Mg 2+ concentrations. This method also improved the thermal stability of the samples. The quantum yield of Mg-modified ZnGa 2 O 4 :Cr 3+ phosphors reached 87.12%, and the white LED fabricated with Zn 0.4 Mg 0.6 Ga 2 O 4 :0.01Cr 3+ phosphor and commercial Y 3 Al 5 O 12 :Ce 3+ phosphor demonstrated good performance. The NIR-LED fabricated with Zn 0.4 Mg 0.6 Ga 2 O 4 :0.01Cr 3+ phosphor achieved a photoelectric conversion efficiency of 7.17%. The lines on the surface of an orange taken by a NIR camera reveal that phosphor can be used in night vision lighting. Meanwhile, the distribution of blood vessels in the human palm highlights the promising biological applications of the Zn 0.4 Mg 0.6 Ga 2 O 4 :0.01Cr 3+ phosphor.