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.