“…Sharp excitation peaks are visible in the excitation spectrum of KYC:3%Dy 3+ . These peaks are observed at 325, 339, 351, 365, 386, 428, 453, and 476 nm and correspond to the transition of Dy 3+ from 6 H 15/2 to 6 P 3/2 , 4 I 9/2 , 6 P 7/2 , 6 P 5/2 , 4 I 13/2 , 4 G 11/2 , 4 I 15/2 , and 4 F 9/2 [ 5 , 28 ], respectively. When Ce 3+ was added to KYC:3%Dy 3+ , two broad absorption peaks were detected at 274 and 340 nm (monitoring at 577 nm), which belong to the energy transition of Ce 3+ from 4f to 5d [ 30 ].…”