CHEM01200604004 Shri Sanyasinaidu Boddu - Homi Bhabha ...

of surface Tb 3+ ions from stabilizing ligands resulting in a single exponential decay curve
corresponding to the 5 D 4 level of Tb 3+ from the sample.
BiPO 4 nanomaterials with hexagonal and monoclinic crystal structures have been
prepared in ethylene glycol medium at a relatively low temperature. There exist solid solution
formation between BiPO 4 and different Ln 3+ ions (like La 3+ , Eu 3+ and Tb 3+ ) as confirmed
from XRD, FTIR and solid-state MAS NMR experiments. This type of solid solutions
formation is highly desirable for making efficient light emitting and light harvesting
materials. Orange, red, green and yellow emission has been observed from Sm 3+ , Eu 3+ , Tb 3+
and Dy 3+ doped BiPO 4 nanomaterials, respectively. In the case of Eu 3+ -Tb 3+ co-doped
samples energy transfer has been observed from Tb 3+ to Eu 3+ .
ZnGa 2 O 4 nanoparticles with tunable sizes have been prepared at a relatively low
temperature of 120°C. Particle size of ZnGa 2 O 4 nanoparticles can be tuned by either varying
the precursor concentration or by varying the viscosity of the reaction medium.
Photoluminescence from these nanoparticles can be tuned from 385 nm to 470 nm by varying
the particle size. Luminescence from the ZnGa 2 O 4 nanoparticles also gets tuned by In 3+
doping in the lattice. Intense blue emission with quantum yield of ~10% is observed from
ZnGa 1.5 In 0.5 O 4 nanoparticles. These nanoparticles were incorporated in PMMA matrix and
such composite materials are useful for developing polymer based display devices. Doping
lanthanide ions like Eu 3+ , Tb 3+ and Ce 3+ in ZnGa 2 O 4 nanoparticles lead to the development of
multicolour light emitting nanoparticles
Un-doped and lanthanide ions doped MWO 4 (M = Ca, Sr, Ba) nanoparticles were
prepared at room temperature in ethylene glycol medium. Under identical conditions, particle
size increases with increase in ionic size of the metal ions. Blue emission is observed from
CaWO 4 nanoparticles and this emission intensity increases with increase in particle size.
Bright orange, red, green and greenish yellow emissions are obtained from Sm 3+ , Eu 3+ , Tb 3+
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