Preparation of BaAl2-xGaxSi2O8:Ce3+, M+ (Li, Na, K) blue-cyan phosphors based on charge compensation and cation substitution strategies and luminescence performance study

Highly efficient blue -cyan phosphors can fill the cyan gap in conventional white light -emitting diode (LED) devices to improve the spectral continuity while effectively increasing the white LED colour rendering index (Ra). In this study, Ba0 & sdot;94Al2-xGaxSi2O8:0.06Ce3+, M+ (Li, Na, K, x = 0-0.8) blue -cyan phosphors with a feldspar structure were prepared by a high -temperature solid -phase method using charge compensation and cation substitution strategies. The barium (Ba) vacancy due to the charge -imbalance substitution of Ce3+ is compensated by the different charge compensators Li+, Na+, and K+. The charge compensators affect the luminescence performance of the samples, with the K+ -compensated samples showing the greatest enhancement, with intensities up to 1.8 times that of the uncompensated samples. The cation substitution strategy using Ga3+ to partially replace Al3+ further improves the luminescence performance of the Ba0 & sdot;94Al2Si2O8:0.06Ce3+, 0.04 K+ sample, and the excitation band is also improved. In this case, the luminescence intensity of the Ba0 & sdot;94Al2Si2O8:0.06Ce3+ luminescent material is increased by a factor of 6, and a broadband blue -cyan phosphor with a full -width at half -maximum of 118 nm containing blue, cyan and green is obtained. The co -doping of charge compensators and partial cation substitution improved the luminescence performance of phosphors. The representative sample Ba0 & sdot;94Al1.6Ga0.4Si2O8:0.06Ce3+, 0.04 K+ has a luminescence intensity at a temperature of 150 degrees C that is 83.2% of that at room temperature and good thermal stability. The combination of 365 nm nearultraviolet (NUV) LED chips with Ba0 & sdot;94Al1.6Ga0.4Si2O8:0.06Ce3+, 0.04 K+ and the commercial red powder (Ca, Sr)AlSiN3:Eu2+ yields a white LED device with an Ra of up to 93 and a correlated colour temperature (CCT) of 4825 K. These results show that the blue -cyan phosphor complements the cyan component while simplifying the manufacturing process of white LEDs.