Sensitizing Eu3+ with Ce3+ and Tb3+ to Make Narrow-Line Red Phosphors for Light Emitting Diodes

The development of efficient, narrow-line emitting materials is one goal for phosphor development in light emitting diode (LED) systems. This Letter describes the Ce 3+ → (Tb 3+ ) n → Eu 3+ energy transfer process that enables Eu 3+ 7 F 0 → 5 D J line emission to be sensitized by the allowed Ce 3+ 4f 1 → 5d 1 absorption transition in near-UV and violet spectral regions. This energy transfer process is demonstrated in YBO 3 :Ce, Tb, Eu powders, leading to line-emitting red phosphors that can be excited by short-wavelength InGaN LEDs. The quantum efficiency of unoptimized YBO 3 :Ce, Tb, Eu powder samples can be 65% of YBO 3 :Ce, Tb or YBO 3 :Ce samples. Limitations for phosphors that use this energy transfer process are discussed.