Single-phased CaAl2Si2O8:Tm3+, Dy3+ white-light phosphors under ultraviolet excitation

► Energy transfer from Tm3+ to Dy3+ was investigated.
► Color tunable from blue to white can be achieved.
► White light can be realized in CaAl2Si2O8:Tm3+, Dy3+ phosphor.

A novel white-light-emitting phosphor CaAl2Si2O8:Tm, Dy was synthesized in ambient atmosphere by solid-state reaction. The energy transfer from Tm3+ to Dy3+ ions via a dipole–quadrupole reaction was observed and investigated. Upon UV excitation, white light emission was achieved by integrating a blue emission band located at 455 nm and an orange one located at 574 nm attributed to Tm3+ and Dy3+ ions, respectively. In addition, the energy-transfer efficiency and critical distance were calculated. Results suggested that the phosphor might be promising as a single-phased white-light-emitting phosphor for UV white-light LED.

The results indicate the existence of energy transfer from Tm3+ to Dy3+. By tuning the concentration of Dy3+, single-phased white light can be realized. Figure optionsDownload as PowerPoint slide