Tunable photoluminescence and site occupancy of activators Ce3+ in novel phosphors Ca3(1−x)ZrSi2O9:3xCe3+

The novel Ce3+-activated blue-emitting phosphors Ca3(1−x)ZrSi2O9:3xCe were successfully obtained by solid-state reaction method in the air atmosphere. Two sets of individual photoluminescence spectra were observed in Ca3(1−x)ZrSi2O9:3xCe. In the two sets of spectra, the maximums of excitation and emission bands locate at about 324, 370 nm (denoted as spectra “EX:324, EM:370”) and 358, 410 nm (denoted as spectra “EX:358, EM:410”), respectively. By analyzing the crystal structure and photoluminescence spectra of Ca3(1−x)ZrSi2O9:3xCe, it can be concluded that the spectra “EX:324, EM:370” originated from Ce3+(1,3) ions occupying Ca2+(1) and Ca2+(3) sites, and the spectra “EX:358, EM:410” are due to Ce3+(2) ions occupying Ca2+(2) sites. Further, the emission band of Ca3(1−x)ZrSi2O9:3xCe is tunable, and the emission peaks red shift with the increase of excitation wavelength and Ce3+ doping concentration. The decay times of Ce3+ ions in Ca3(1−x)ZrSi2O9:3xCe phosphors are short in tens of nanoseconds. Moreover, the photoluminescence thermal stability of Ca3(1−x)ZrSi2O9:3xCe (x = 0.02) is acceptable, especially under the 324 nm excitation, and the relative emission intensity at 100 °C remains to be about 91% of the initial value at room temperature. Thus, Ca3(1−x)ZrSi2O9:3xCe is a kind of promising blue-emitting phosphors that can be potentially used in ultraviolet excited white light-emitting diodes (WLEDs), agriculture and other photonic fields.