Photoluminescence properties of tunable full-color-emitting CaZrO3: Ln (Ln = Tb3+, Eu3+, Tb3+/Eu3+) phosphors for white LEDs

A series of single-phase color-turning CaZrO3: Ln (Ln = Tb3+, Eu3+, Tb3+/Eu3+) phosphors was synthesized through citric acid-fueled combustion method. The as-prepared samples had the perovskite structure with Pnma space group and elements uniformly distributed in nanosized particles. CaZrO3: Eu3+ phosphor produced red luminescence due to the 5D0→7F2 transition at 619 nm CaZrO3: Tb3+ phosphor produced green and blue luminescence due to the 5D4→7F6, 5 transition at 487 nm and 548 nm. Under UV irradiation at 254 nm, the CaZrO3: Ln (Ln = Tb3+, Eu3+, Tb3+/Eu3+) phosphors achieved tunable full-color emission in a wide range from blue to green, warm white, and red. The corresponding CIE coordinates were (0.2546, 0.2413), (0.3196, 0.5085), (0.3603, 0.3896) and (0.6089, 0.3844). The energy transfer from ZrO32− to Tb3+ and then to Eu3+ was determined by the dipole-dipole mechanism in CaZrO3: 0.03 Tb3+, xEu3+ phosphors. The excellent temperature stability of CaZrO3: 0.03 Tb3+, 0.01Eu3+ phosphor (ΔE = 0.2659 eV) indicates that CaZrO3: Ln (Ln = Tb3+, Eu3+, Tb3+/Eu3+) phosphors have broad application prospects in W-LED devices.