Color tunable and white light emitting via energy transfer in single-phase BiOCl:Er3+,Sm3+ phosphors for WLEDs

BiOCl crystal shows potential as efficient optical host due to its special layered structure. Here, the luminescence properties of the Er³⁺/Sm³⁺ co-doped BiOCl phosphors as single-phase phosphors were reported. Upon near ultraviolet excitation (NUV, 380 nm corresponding the ⁴I_15/2 → ⁴G_11/2 transition of Er³⁺ ions), the phosphors exhibit the efficient characteristic emissions of Er³⁺ and Sm³⁺ ions simultaneously. The energy transfer (ET) from Er³⁺ to Sm³⁺ ions in the layered crystals has been validated by the variation of emission intensities and decay lifetimes respectively, which is ascribed to be a dipole–dipole interaction. By virtue of the ET behavior and increasing Sm³⁺ ion concentration, the enhancing emission intensity of Sm³⁺ and the tunability of emission color from yellowish-green (0.318, 0.420) to white (0.343, 0.347) are realized. The results of our work indicate that the Er³⁺/Sm³⁺ co-doped BiOCl phosphor has a promising application serving as single component white emitting phosphors for NUV excited WLEDs.