Li+ doping induced zero-thermal quenching in Cs3Zn6––B9O21:xEu3+,yLi+ (0 ≤ x ≤ 0.10, 0.06 ≤ y ≤ 0.16)

Thermal stability is a crucial index to assess application value of high-power LEDs, which is related to lattice defects. Herein, an effective structure-engineering strategy is proposed to achieve excellent properties. Under the 394 nm excitation, Cs3Zn5.94B9O21:0.06Eu3+ possesses two characteristic emissions peaked at 591 and 612 nm with limited thermal stability. By introducing Li+ ions into the lattice, the sample exhibits high color purity and excellent zero-thermal quenching because the defect contents of the phosphor can be effectively modulated via charge-compensation effect. Then, under the stimulus of high temperature, the corresponding trap levels with a suitable depth (E = 1.27 eV) will release electrons to recombine with the luminescent centers, compensating for the energy loss. The study provides a meaningful guide for optimizing and designing novel functional photoluminescent materials.