A red-emitting perovskite-type SrLa(1−x)MgTaO6:xEu3+ for white LED application

Abstract

A narrow high intensity red-emitting double-perovskite type phosphor SrLa1−xMgTaO6:xEu3+ was successfully synthesized by a solid-state reaction method. Under the excitation of the near UV and blue light, this phosphor exhibited intense red emission that can improve the color qualities of warm light-emitting diodes. Due to the Eu3+ ions being an intrinsically asymmetric cation environment, the dominant emission peak emitted from the transition 5D0→7F2 is extraordinarily stronger than that of 5D0→7F1, the ratio I0−2/I0−1 was about 8.67. And owing to the most Eu3+ ions locating at same crystal field environment, a full-width at half-maximum (FWHM) of this peak was very narrow (6.49nm) at room temperature. Energy transfer between Eu3+ ions were demonstrated from dipole–dipole interaction, and the critical distance was estimated to be 9.31Å. When Eu3+ ions' concentration reaches 30%, the emission intensity was observed about three times higher than that of a commercial red phosphor Y2O3:Eu3+, and the Commission International de L’Eclairage chromaticity coordinates was calculated at (0.66, 0.33). All the results confirmed that SrLa(1−x)MgTaO6:xEu3+ phosphors might be promising for use in white LEDs.