Ba3P4O13:Eu3+ phosphors with high thermal stability and high internal quantum efficiency for near-ultraviolet white light-emitting diodes

The studied samples, which were sintered by a sol–gel technique, can be efficiently pumped by the near-ultraviolet light and emitted bright red light arising from the 4f–4f transitions of Eu3+ ions. Besides, color coordinate and internal quantum efficiency of the synthesized phosphors were determined to be (0.621, 0.378) and 71.2%, respectively. The optimum doping concentration for the Eu3+ ions in the Ba3P4O13 host lattices was revealed to be 10 mol% and the concentration quenching mechanism was dominated by electric-dipole interaction. By a facile method utilizing the Judd–Ofelt theory, the intensity parameters were calculated to analyze the local crystal environment surrounding the Eu3+ ions in the Ba3P4O13 host lattices. Furthermore, the temperature-dependent PL emission spectra confirmed that the studied compounds still remained 80.7% of its initial PL emission intensity at room temperature, indicating its excellent thermal stability. Ultimately, a light-emitting diode device, which can emit bright white light with proper correlated color temperature (CCT = 6727 K) and color rendering index (CRI = 73.2) values, was packaged to explore the feasibility of the final products for indoor illumination applications.