Preparation and luminescent properties of white-emitting Sr(Ca)GdAlO4: Dy3+/Tm3+phosphors

A series of Dy3+/Ca2+/Tm3+ doped and co-doped SrGdAlO4 phosphors were synthesized by high-temperature solid-state method, and their structure, morphology, and optical property were tested and characterized. The XRD showed that a small amount of doping with Ca2+, Dy3+ and Tm3+ does not change the crystal structure of the matrix SrGdAlO4, and that the optimal synthesis temperature and holding time is 1500 degrees Cand 3 h. The SEM showed that the particle size is roughly between 1 and 40 mu m. The SrGdAlO4: Dy3+, SrCaGdAlO4: Dy3+/Tm3+ and SrCaGdAlO4: Dy3+ phosphors could be efficiently excited by near-ultraviolet wavelength, and produced two strong emission peaks at 484 nm (blue) and 580 nm (yellow); the SrCaGdAlO4: Dy3+/Tm3+ phosphor can show the characteristic emission peaks of Dy3+ and Tm3+ at the same time at the same excitation wavelength. The modulation of SrCaGdAlO4: Dy3+/Tm3+ phosphor from warm white light to cold white light can be achieved by changing the relative doping concentration ratio of Dy3+ and Tm3+. In addition, studies on the luminescence mechanism and lifetime show that there is an energy transfer between Dy3+ and Tm3+ in the SrCaGdAlO4: Dy3+/ Tm3+ phosphor.