Red, green and blue-violet emission coexistence in white-light-emitting Ca3SiO4Cl2:Bi3+, Li+, Eu2+, Eu3+ phosphor

A series of emission-tunable Ca3SiO4Cl2:Bi3+, Li+, Eun+(n =2, 3) (CSC:Bi3+, Li+, Eun+) phosphors have been synthesized via sol-gel method. The X-ray diffraction results indicate that the as-synthesized phosphors crystallize in a low temperature phase with the space group of P21/c. Energy transfer from Bi3+ to Eu3+/Eu2+ exists in CSC:Bi3+, Li+, Eun+ phosphors. Under the excitation of 327 or 365 nm, the Ca2.98−ySiO4Cl2:0.01Bi3+, 0.01Li+, yEun+(y=0.0001-0.002) phosphors show an intense green emission band around 505 nm, while under the excitation of 264 nm, three emission bands centered around 396 nm (Bi3+), 505 nm (Eu2+) and 614 nm (Eu3+) are observed and tunable colors from blue-violet to green or white are achieved in these phosphors by varying the content of Eu. White-light emission with the color coordinate (0.312, 0.328) is obtained in Ca2.978SiO4Cl2:0.01Bi3+, 0.01Li+, 0.002Eun+(n =2, 3). Based on these results, the as-prepared CSC:Bi3+, Li+, Eu2+, Eu3+ phosphors can act as color-tunable and single-phase white emission phosphors for potential applications in UV-excited white LEDs.