Structural, Raman,
and optical properties of sol–gel derived
Zn1–x
Mn
x
O (0≤x ≤ 0.06) nanoparticles have
been investigated. The crystallite structure, morphology, and size
estimation have been performed by X-ray diffraction (XRD) and high-resolution
transmission electron microscopy (HRTEM). To study the crystalline
quality, structural disorder and defects in the host lattice, we have
employed Raman Spectroscopy. The wurtzite structure and formation
of tetrahedral coordination of the oxygen ions surrounding the zinc
ions has been confirmed by FTIR analysis. Optical properties have
been studied by UV–vis and PL spectroscopy. UV–vis measurements
show that the band gap is increased with increasing Mn concentration.
This may be attributed to the orbital hybridizations that are prevailed
throughout the whole range of Mn doping. Variation of resistivity
with temperature shows that thermally activated conduction (Arrhenius)
mechanism is valid in the high-temperature region (T > 250 K), whereas Mott’s variable-range hopping (VRH)
mechanism
is valid in low-temperature region (T < 250 K).
Variation of the activation energy estimated from the resistivity
measurement (Arrhenius law) qualitatively follows the variation of
the optical band gap.