Overcoming the cyan gap for full‐spectrum lighting using cation‐substitution‐induced rigid Ca₂YZr₂Al₃O₁₂:Ce³⁺

Abstract

Mixing multicolor phosphors for simulating the full spectrum of sunlight illumination is a popular solution to obtain high‐quality white light. However, there is still a need to overcome the cyan gap in the emission spectrum. In this work, a series of garnet Ca2Y0.94–xLuxZr2–yHfyAl3O12:6%Ce3+ (abbreviated as CY0.94–xLuxZr2–yHfyA:Ce3+) cyan phosphors are designed and prepared by substituting Y3+ and Zr4+ in Ca2YZr2Al3O12:6%Ce3+ with Lu3+ and Hf4+ with smaller ionic radius and larger mass. Under 405 nm violet light excitation, the optimized Ca2Y0.88Lu0.06Hf2Al3O12:6%Ce3+ (CY0.88Lu0.06Hf2A:Ce3+) shows a bright cyan emission band in the range of 430–750 nm with the peak at 477 nm. Importantly, the emission intensity and thermal stability properties of CY0.88Lu0.06Hf2A:Ce3+ were significantly improved by 58% and 47% compared to those of pure Ca2YZr2Al3O12:Ce3+. Small and heavy cation substitution could induce highly stable rigid structure, thus enhancing emission intensity and stability. The color rendering index increases from 84.5 to 92.0 after supplementing CY0.88Lu0.06Hf2A:Ce3+ phosphor in white light‐emitting diode devices combining commercial red, green, and blue phosphors with a violet chip, indicating its practical application in full‐spectrum lighting. The present study provides promising strategies for the design and development of efficient cyan materials for high‐quality full visible spectrum light‐emitting diode lighting.