Ba²⁺‐Si⁴⁺‐Incorporated High‐Efficiency and Excellent Thermal Stable YAG:Ce³⁺ Ceramic Phosphors for Laser‐Driven Lighting

Abstract Y₃Al₅O₁₂:Ce³⁺ (YAG:Ce³⁺) ceramic phosphor (CP) is the predominant color convert utilized in laser‐diode (LD) driven lighting. How to obtain a high‐efficiency CP is the challenge. A strategy to depress lattice defects by the Ba²⁺‐Si⁴⁺ replacement for the Y³⁺‐Al³⁺ pair is proposed. On the basis of charge equilibrium, the heavy element Ba also can enhance the thermal stability of CPs. The luminous intensity at 200 °C is improved from 83% to 97% of that at room temperature, and then the luminous efficiency reaches 262 lm W⁻¹ from blue lasers to white light. The luminous flux of the white LD flashlight using the CP increases by 30% compared with that of the commercial LD flashlight. These results demonstrate that the strategy is effective in optimizing YAG:Ce³⁺ CP performance. The luminescence saturation coupled with optics and heat is investigated.