A novel red phosphor Sr3In2WO9: Eu3+ for WLEDs

Abstract

A series of Sr3In2WO9: xEu3+ red phosphors were prepared using a solid-state reaction. The strongest excitation peak of Sr3In2WO9: xEu3+ appeared at 394 nm, and the strongest emission peak appeared at 612 nm. The concentration-dependent emission spectra show that the optimal doping concentration of Eu3+ ions is x = 0.30 for all Sr3In2WO9: xEu3+ samples and Eu3+ occupies the non-inverted centrosymmetric site. Analysis of the causes of concentration quenching, the dipole-quadrupole interaction in Sr3In2WO9: xEu3+ was determined to be the main cause. The thermal stability of the Sr3In2WO9: 0.30Eu3+ sample was analyzed, and it was found that the luminescence intensity of the Sr3In2WO9: 0.30Eu3+ was retained by 55.1 % at 423 K. The thermal quenching activation energy ΔE = 0.291 eV was calculated after the thermal quenching analysis. The calculated CIE chromaticity coordinate of Sr3In2WO9: 0.30Eu3+ is (0.6450, 0.3544), which are very close to the standard red light (0.667, 0.333) given by the National Television Standards Committee system. The color purity of all samples is above 95 %, and the associated color temperature is below 2400 K. The chromaticity coordinates of the encapsulated WLED point of (0.329, 0.388) with a lower correlation color temperature of 5841 K and excellent color rendering index of 88, which indicated the near-UV excited SIWO: Eu3+ red phosphor has great potential for application in the field of WLEDs devices.