Thermally Stable Pyrochlore Y ₂ Ti ₂ O ₇ : Eu ³⁺ Orange–Red Emitting Phosphors

Pyrochlore‐structured Y 2 Ti 2 O 7 doped with Eu 3+ activators via high‐temperature solid‐state reaction shows thermally stable orange‐red emission under near ultraviolet excitation. The concentration of Eu 3+ activators was observed to influence both the intensity and color point of photoluminescence of Y 2−x Ti 2 O 7 : x Eu 3+ phosphors. The optimal doping concentration is around x = 0.45 determined by photoluminescence intensity; at this concentration, the luminescence branch ratio , named as the luminous intensity ratio of 5 D 0 – 7 F 2 (R) and 5 D 0 – 7 F 1 (O) transition is also at maximum, about 0.46. This orange–red emitting phosphor Y 1.55 Ti 2 O 7 :0.45 Eu 3+ shows excellent thermal stability in luminescence intensity, retaining 84% of room‐temperature luminescence at 250°C. Therefore, Y 1.55 Ti 2 O 7 :0.45 Eu 3+ phosphors may have great potential as an orange–red component for white light‐emitting diodes, especially for the high‐power devices.