Preparation and characterization of rare earth (Pr, Nd) doped ZnO nanoparticles

Pr and Nd doped ZnO nanoparticles are prepared by simple chemical route and precursors used are ZnCl
₂
and NaOH. From XRD patterns, the particles size are found to be 15, 16, 17 nm for 1 wt%, 2 wt% and 3 wt% of Pr doped ZnO nanoparticles respectively and 17,18, 19 nm for 1 wt%, 2 wt% and 3 wt% of Nd doped ZnO nanoparticles respectively. Absorption studies are carried out from 200 to 800 nm. The ZnO cut off wavelength of both the Pr and Nd doped are found near 346 nm. Pr
³⁺
absorption peaks are found at 446, 463 and 589 nm and these correspond to transitions from the ground state of
³
H
₄
to
³
P
₂
,
³
P
₁
and
¹
D
₂
and Nd
³⁺
absorption peaks are found at 520, 578, 738 and 799 nm and these correspond to transitions from the ground state of
⁴
I
_9/2
to
⁴
G
_7/2
,
⁴
G
_5/2
+
²
G
_7/2
,
⁴
S
_3/2
+
⁴
F
_7/2
,
⁴
F
_5/2
+
²
H
_9/2
. Photoluminescence studies of the sample are also made and excitation wavelength was 325 nm. Emission bands characteristic of Pr
³⁺
are observed at 450, 469, 482 and 493 nm for samples, which corresponds to
³
H
₄
->;
³
P
₂
,
¹
I
₆
->;
³
H
₄
,
³
P
₁
->;
³
H
₄
and
³
P
₀
->;
³
H
₄
transitions, respectively. Emission bands characteristic of Nd
³⁺
are observed at 450, 473, 480 and 530 nm for samples, which corresponds to
²
P
_3/2
->;
⁴
I
_13/2
,
²
P
_3/2
->;
⁴
I
_15/2
,
²
P
_1/2
->;
⁴
I
_11/2
and
⁴
G
_7/2
->;
⁴
I
_9/2
transitions, respectively. FTIR spectra show the Zn-O stretching at 535 cm
^-1
for the Pr doped and at 544 cm
^-1
for Nd doped ZnO nanoparticles. High resolution SEM images are taken and morphology of the particles was reported.