Variation of Eu3+ emissions in yttrium aluminum oxides controlled by amount of La3+ dopant

The nanophosphors of europium doped yttrium aluminum oxide were synthesized by a hydrothermal method. As the amount of La3+ ions substituted in yttrium sites was increased, the crystal structure was transformed from pure garnet to perovskite phase through the mixed phase of garnet and perovskite. Red emission centered at 618 nm wavelength radiated from a 5D0 → 7F2 of Eu3+ due to the forced electric dipole transition was remarkably enhanced by a factor 45, which is attributed to the phase transition of yttrium aluminum oxide by incorporation of La3+ ions.