Tunable warm white light emission and energy transfer of Dy co-doped Sr LaZrO :Eu phosphors.

Eu ,Dy co-doped Sr LaZrO -based phosphors were prepared through a sol-gel method. Through characterization, it was found that the Sr LaZrO -based fluorescent powder co-doped with Eu and Dy had a cubic structure. At an excitation wavelength of 290 nm, the substrate Sr LaZrO exhibited strong blue emission at 468 nm, and the Sr LaZrO :18%Eu phosphor exhibited a strong red emission peak at 612 nm. When the doping amount of Dy was 5, 8, 12, 15, or 18%, the Sr LaZrO :18%Eu phosphor changed from an orange-red light, to a warm white light, and to a cold white light. According to the emission spectra, the emission intensities of the substrates Sr LaZrO and Sr LaZrO :Eu decreased with increasing Dy concentration, confirming the energy transfer between the host Sr LaZrO -Eu ,Dy , and resulting in a lower CCT value, with significantly improved white light emission.