Far-red emitting Li2TiO3: Cr3+ phosphor: Synthesis, luminescence properties and potential applications

The Cr 3 + -activated phosphor can emit far-red light under the excitation of an external light source, mainly due to the transition of the outermost electrons of Cr 3 + from the 2 E level to the 4 A 2 level in a strong crystal field environment. A novel far-red Li 2 TiO 3 : Cr 3 + phosphor was prepared by the solid-state method. Under the excitation of 356 nm, the Li 2 TiO 3 : Cr 3 + phosphors emit intense far-red light in 600–850 nm with a central wavelength of 732 nm. The emission band of all samples was matched with the absorption bands of phytochrome P F R . The experimental data and theoretical calculation confirmed that Cr 3 + is surrounded by a strong crystal field environment. The effect of Cr 3 + doping concentration on the luminescence intensity was analyzed. These research works demonstrate that far-red Li 2 TiO 3 : Cr 3 + phosphors have potential applications in plant growth lights.