CHEM01200604004 Shri Sanyasinaidu Boddu - Homi Bhabha ...

Ce 3+ in the lattice leads to significant strain in the lattice due to large ionic size of Ce 3+ ion
compared to Ga 3+ ion.
Emission spectrum of 5 atom % Ce 3+ doped ZnGa 2 O 4 nanoparticles after exciting at
265 nm light is shown in the Fig.103 (a) along with the corresponding excitation spectrum
monitored at 350 nm emission. Emission spectrum shows broad band at 350 nm and is
assigned to the 5d-4f transition of Ce 3+
ion in the ZnGa 2 O 4 host. The corresponding
excitation spectrum shows a band at 265 nm and is arising due to the 4f-5d transition of Ce 3+
ion. The decay curve corresponding to Ce 3+ emission at 350 nm is shown in Fig.103 (b). The
decay is single exponential with lifetime of 17.3 ns. Based on the studies it can be inferred
that Ce 3+ doping in ZnGa 2 O 4 will be helpful for making bright luminescent materials showing
emission in the UV region.
Intensity (arb.units)
ZnGa 2
O 4
:5 % Ce 3+
ZnGa 2
O 4
10 20 30 40 50 60 70
Fig.102. XRD patterns of undoped ZnGa 2 O 4 and 5 at % Ce 3+ doped ZnGa 2 O 4 nanoparticles.
2θ/°
Normalised intensity
1.0
0.8
0.6
0.4
0.2
Excitation scan
Emission scan
1000
0.0
1
200 250 300 350 400 450 500
50 100 150 200
Wavelength (nm)
Time (ns)
(a)
(b)
Fig.103. (a) Emission and excitation spectra of 5 at % Ce 3+ doped ZnGa 2 O 4 nanoparticles and
(b) excited state decay profile of Ce 3+ emission (λ exc =265 nm, λ em =350 nm).
Intensity (arb.units)
100
10
162