“…19,36 Obviously, the two strongest peaks at 393 and 465 nm, originating from the 7 F 0 / 5 L 6 and 7 F 0 / 5 D 2 transitions of the Eu 3+ ions, respectively, can be observed, which illustrate the prepared sample can be excited by the near ultraviolet and blue LED chips effectively. 36 Upon excitation at 393 nm, several emission peaks from 550 to 750 nm, corresponding to the electronic 5 D 0 / 7 F i (i ¼ 0, 1, 2, 3, 4) transitions, are present in the PL spectrum. 3 The most intense emission peak at 612 nm and four other weaker emission peaks at 579, 594, 653 and 707 nm can be found, which are in good agreement with the 5 D 0 / 7 F 2 , 5 D 0 / 7 F 0 , 5 D 0 / 7 F 1 , 5 D 0 / 7 F 3 and 5 D 0 / 7 F 4 transitions of the Eu 3+ ions, respectively.…”