UV Emission from the Second Lowest 5d State in Ce³⁺: YAG

Luminescence and defects creation in Ce3+‐doped Lu3Al5O12 crystals

“…The intensity ratio of these emissions (I 2.46 eV /I 3.12 eV = 145) in LuAG:Ce is much smaller than in YAG:Ce where the value of 909 is reported [11]. The intensity ratio of the higher-energy emission component (5d -2 F 5/2 ) to the lower-energy emission component (5d -2 F 7/2 ) is practically the same for both the ultraviolet and the visible emission.…”

Luminescence of undoped LuAG and YAG crystals

“…Defects, responsible for these bands, compete with Ce 3+ in the energy transfer processes and reduce considerably the efficiency of energy transfer from the host lattice to Ce 3+ ions [2]. The luminescence of undoped YAG crystals was studied in numerous papers (see, e.g., [1][2][3][4][5][6][7][8][9][10][11][12][13] and references therein). Under excitation in the exciton absorption region (near 7.0 eV [3,4,8]), the presence of two ultraviolet emission bands was reported.…”

“…In the luminescence spectrum of YAG:Ce and LuAG:Ce crystals, besides the Ce 3+ -related intense green and weak ultraviolet bands (see, e.g. [1,2]), additional ultraviolet bands are observed, which are present also in undoped single crystals of YAG [3][4][5][6][7][8][9][10][11][12] and LuAG [2]. Defects, responsible for these bands, compete with Ce 3+ in the energy transfer processes and reduce considerably the efficiency of energy transfer from the host lattice to Ce 3+ ions [2].…”

Strong visible and near infrared luminescence in undoped YAG single crystals

“…16 However according to the current measurements, undoped YAG has multiple strong luminescence peaks, not only the 300 nm emission, which has been the focus of all the previous investigations on YAG crystals. [6][7][8][9][10][11][12][13][14][15][16] The UV emission in YAG has been suggested to result from self trapped excitons and antisite defects Y Al 3+ , 16 which have low formation energy as predicted by first principals calculations. 17 We attribute the new observed PL emission bands at 700 and 800 nm to Fe 3+ impurities for the following reasons: 1) Fe 3+ in either tetrahedral or octahedral sites has a broad emission in many materials between 700 nm 1000 nm; 18 and according to EPR studies, 19 Fe ion substitutes for the Al ion at both octahedral and tetrahedral sites in the YAG structure.…”

“…2 The luminescence of undoped YAG crystals has been extensively studied. [8][9][10][11][12][13][14][15] However, most of the measurements have focused on the UV emission and identified it as the main luminescence in the YAG structure and the main defect center that compete with Ce 3+ ion in Ce doped YAG (Ce:YAG) scintillators.…”