CHEM01200604004 Shri Sanyasinaidu Boddu - Homi Bhabha ...

Similar results are also observed from β-Ga 2 O 3 :Eu nanorods obtained after the
decomposition of GaOOH:Eu nanorods at 900°C, as can be seen from the emission and
excitation spectra shown in Fig.40 (c and d). The patterns match well with that reported for β-
Ga 2 O 3 :Eu films by Mizunashi and Fujihara [204]. Unlike the excitation spectrum observed
for Ga 2 O 3 :Dy nanorods (Fig.40 (b)), the excitation spectrum corresponding to Ga 2 O 3 :Eu
nanorods is characterised by a broad peak with emission maximum around 280 nm. This has
been attributed to the overlapping of Eu-O charge transfer band with the Ga 2 O 3 host
excitation peak.
Figure 41 shows the emission and excitation spectra of Er 3+ doped Ga 2 O 3
nanomaterials. Emission spectrum (Fig.41 (a)) after excitation at 380 nm shows strong peak
at 1535 nm corresponding to 4 I 13/2 → 4 I 15/2 transition of Er 3+ ions present in the Ga 2 O 3 lattice.
The excitation spectrum (Fig.41 (b)) corresponding to 1535 nm emission consists of many
sharp peaks and are attributed to f-f transitions of Er 3+ ion in the Ga 2 O 3 lattice. Based on
these studies it is confirmed that β-Ga 2 O 3 is an ideal host for doping lanthanide ions. Efficient
energy transfer from host to lanthanide ions helps to improve photoluminescence from
lanthanide ions.
50000
4 I 15/2
4 G 11/2
λ em
= 1535 nm
Intensity (arb.units)
40000 4 I 13/2
30000
λ
20000 exc
= 380 nm
10000
0
Intensity (arb.units)
40000
30000
20000
10000
0
2
H9/2
4
I15/2
4
F5/2
4
I15/2
4 4
I15/2 F7/2
4 I 15/2
2 H 11/2
4 4
I15/2 S3/2
4
I 15/2
1300 1400 1500 1600
Wavelength (nm)
(a)
(b)
350 400 450 500 550 600
Wavelength (nm)
Fig.41. (a) Emission spectrum and (b) excitation spectrum from Ga 2 O 3 :Er 3+ nanorods. The
excitation and emission wavelengths are 380 and 1535 nm, respectively.
85