Enhancement of red emission intensity of Ca9Y(VO4)7:Eu3+ phosphor via Bi co-doping for the application to white LEDs

► Ca9Y(VO4)7:0.15Bi3+, 0.8Eu3+ (excited at 395/465 nm) has a stronger brightness than Y2O3:Eu3+ (excited at 395/467 nm). ► The energy transfer from Bi3+-V5+ to Eu3+ is discussed. ► Based on the R/O value, the symmetry of Eu3+ site decreases with doping of Bi3+. ► The present material can be potentially used for LEDs with near-UV/blue GaN-based chips.