Synthesis and characterization of thermostable Dy3+-doped La5NbMo2O16 yellow-emitting phosphors for w-LEDs

In order to develop new phosphors, a series of novel trivalent dysprosium (Dy3+) activated single-phase yellow-emitting La5NbMo2O16 phosphors were firstly prepared through the high-temperature solid-state reaction method. Powder X-ray diffraction (XRD) patterns were measured to check the crystalline structure of La5NbMo2O16 phosphors. The photoluminescence (PL) spectra were used to characterize the luminescence properties of the prepared La5NbMo2O16:Dy3+ phosphors. Under 386 nm excitation, the PL spectra of La5NbMo2O16:Dy3+ phosphors mainly contain three dominant sharp peaks at blue (486 nm), yellow (574 nm), and red emission (669 nm), respectively. The intense peak at 574 nm attributes to the typical F-4(9/2)-H-6(13/2) transition of Dy3+ ions. The optimal sample is La5NbMo2O16:10 mol%Dy3+ phosphor with the estimated R-c = 18.89 angstrom. The obtained La(5)NbMo(2)O(16)10 mol%Dy3+ product shows high thermostability with high quenching temperature (above 480 K) and good activation energy (E-a = 0.32 eV). Besides, the CIE chromaticity coordinate (0.442, 0.474) of the La5NbMo2O16:10 mol%Dy3+ phosphor is in the yellow region. A white light-emitting diode (w-LED) with the chromaticity coordinates of (0.322, 0.335), a correlated color temperature (CCT) of 5974 K, and a color rendering index (R-a) of 90 was successfully fabricated. All results indicate that La5NbMo2O16:Dy3+ phosphors have extensive application prospects for w-LEDs.

Automated summary

A series of novel trivalent dysprosium activated La5NbMo2O16 phosphors were successfully prepared via solid-state reaction, exhibiting excellent luminescence properties with dominant blue, yellow, and red emissions. The optimal sample, La5NbMo2O16:10 mol%Dy3+ phosphor, showed high thermostability and good activation energy, making it suitable for white light-emitting diode applications.