Luminescence properties and energy transfer of Ce³⁺/Dy³⁺co-activated LaAl_2.03B₄O_10.54 phosphors for wLEDs

Abstract

Dy³⁺ ions doped inorganic materials have attracted extensive attentions for their peculiar white emission and simple preparing process. However, Dy³⁺ ions in these materials have low emission intensity due to the weak absorption in ultraviolet spectral region. Ce³⁺ ions in most of inorganic compounds show a broad emission in ultra-violet region. Thus, Ce³⁺ is an effective sensitizer for Dy³⁺. In this work, a sequence of novel white light-emitting phosphors LaAl_2.03B₄O_10.54: Ce³⁺/Dy³⁺ was synthesized by high-temperature solid-state reaction method. Under the excitation at 310 nm, the luminescence properties and energy transfer behavior were investigated in detail for Ce³⁺/Dy³⁺ co-doped LaAl_2.03B₄O_10.54 phosphors. The energy transfer efficiency from Ce³⁺ to Dy³⁺ was calculated to be 56% with the quadrupole–quadrupole interaction mode. The emitting color of the samples can be modulated from (0.210, 0.123) to white region (0.263, 0.237) by properly changing the doping concentration of Dy³⁺. The results in this work indicate that the color tunable LaAl_2.03B₄O_10.54: Ce³⁺/Dy³⁺ phosphors may be a potential single component phosphor in the field of wLEDs.