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

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.

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.