CHEM01200604004 Shri Sanyasinaidu Boddu - Homi Bhabha ...

shown in Fig.40 (b). While monitoring Dy 3+ emission, observation of host absorption around
260 nm confirms that energy transfer occurs from host to Dy 3+ ions in β-Ga 2 O 3 :Dy 3+
nanorods. A comparison of this emission and excitation spectrum with that of GaOOH:Dy
samples (Fig.28) reveals that the energy transfer is relatively stronger in Ga 2 O 3 :Dy 3+ system
compared to GaOOH:Dy 3+ system. The efficiency of energy transfer has been calculated and
found to be around 92 % in this case. Possible reason for the improved energy transfer is the
combined effect of migration of lanthanide ions in the lattice of Ga 2 O 3 as well as removal of
hydroxyl groups by heat treatment. These observations are in agreement with those reported
on lanthanide ions (Dy 3+ ) doped Ga 2 O 3 nanomaterials [56].
Noramlised Intensity
Normalised Intensity
1.0
0.5
0.0
(a)
1.0
0.5
4 F 6 9/2
H 4 13/2
F 6 9/2
H 15/2
400 450 500 550 600 650
Wavelength (nm)
5 7
D0 F1
5 7
D0 F2
5 7
D0 F3
5 7
D0 F4
Normalised Intensity
(b)
Normalised Intensity
1.0
0.5
0.0
200 250 300 350 400
Wavelength (nm)
1.0
0.5
0.0
500 550 600 650 700 750
Wavelength (nm)
0.0
200 250 300 350 400
Wavelength (nm)
(c)
(d)
Fig.40. Emission spectrum (a) obtained after 260 nm excitation and excitation spectrum (b)
corresponding to 575 nm emission from β-Ga 2 O 3 :Dy 3+ nanomaterials. Corresponding
emission (λ exc = 280 nm) and excitation (λ em = 613 nm) spectrum from Ga 2 O 3 :Eu
nanorods are shown in Fig.40 (c and d).
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