A novel broad-band red K2MgSiO4:Eu2+ phosphor and defect-induced tunable emission from red to yellow

Abstract

Tunable emission in red phosphors is a challenge for the application of wLED. Herein, we reported a new Eu2+ doped oxide based red K2MgSiO4:Eu2+ phosphor. Under excitation at 319 nm, the K2MgSiO4: Eu2+ phosphor exhibits a broad band red emission peaking at 648 nm with FWHM ≈231 nm. The structural and spectral analyses suggest that Eu2+ occupy K1/K3O6 sites and K2/K4O8 sites to form two Gaussian fitting emissions at 732 nm and 629 nm, respectively. To achieve tunable emission, reducing the Si content is attempted in K2MgSi1-yO4:Eu2+. As the Si content decreases from y = 0 to y = 0.04, the emission spectrum shows a blue shift from 648 nm to 523 nm. Therefore, defect-induced color-tunable phosphors from red to yellow are obtained through reducing Si content in the host. This study aims to provide a new research method to guide the development of Eu2+ doped oxide based red phosphors and design idea to obtain tunable emission of phosphors. Moreover, the defect-induced photoluminescence tuning strategy is universal to most luminescent materials.