Realizing Visible Light Excitation of Tb³⁺ via Highly Efficient Energy Transfer from Ce³⁺ for LED‐Based Applications

Abstract Trivalent terbium (Tb³⁺)‐activated luminescence materials usually show highly efficient green emission with the full width at half maximum of merely 10 nm, but suffer from the unsatisfactory excitable wavelength (<380 nm) as well as the inefficient light absorption. Here, the realization of efficient visible light excitation of Tb³⁺ is demonstrated in terbium‐concentrated garnet Ca₂TbHf₂Al₃O₁₂ (CTHA) by introducing Ce³⁺ as the sensitizer. Owing to highly efficient energy transfer from Ce³⁺ to Tb³⁺, CTHA:Ce³⁺ combines advantages of the extra narrow green emission of Tb³⁺ peaking at 544 nm and the efficient broad excitation of Ce³⁺ covering the short‐wavelength visible light from 380 to 450 nm. The color gamut of the prototype white light‐emitting diode (LED) by using CTHA:Ce³⁺ as the green emitter can reach 95% (coverage ratio) of National Television Standards Committee (NTSC) space in Commission Internationale de L'Eclairage (CIE) 1931, indicating its great potential for LED (or laser diode)‐based applications.