Preparation, structure and luminescent properties of Eu3+ doped MBPO5 (M = Ca, Sr, Ba) red phosphor for white LED.

Motivation: A suite of MBPO₅ (borophosphates-BPO):Eu³⁺ (M = Ca, Sr, Ba) red emitting phosphors were synthesized and their luminescent properties were studied by excitation and emission spectra. Results: The energy gap of CBPO, SBPO and BBPO are 5.481, 5.498 and 5.604 eV, respectively. While, these samples showed similar total and partial densities of states. The x-ray powder diffraction (XRD) patterns indicated that the samples were simple MPBO5 phase. According to the absorption spectra, the band gap energies of CBPO:Eu³⁺, SBPO: Eu³⁺ and BBPO:Eu³⁺ were calculated to be 5.499, 5.516 and 5.659 eV, respectively. The spectra of all three MBPO₅:Eu³⁺ samples were similar with main excitation and emission peaks at 394 nm and 594 nm, respectively. The concentration quenching did not appear with the increase of the concentration of Eu³⁺. The charge compensator can improve the emission intensity. The average decay time of CBPO:0.05Eu³⁺, SBPO:0.05Eu³⁺ and BBPO:0.05Eu³⁺ was 3.29, 2.54, and 3.15 ms, respectively. The above results suggested that this phosphor was qualified as red phosphor, which could be used as a near UV-based white LED. [ABSTRACT FROM AUTHOR]