Thickness effect on the properties of Mn-doped ZnO thin films synthesis by sol-gel and comparison to first-principles calculations
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Date
2022
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Université de M'sila
Abstract
The current study investigates the effect of thickness on the structural, morphological, electronic, and optical
properties of pure zinc oxide (ZnO) and 7% Mn-doped ZnO thin films, deposited by sol–gel spin coating method.
All films exhibited a hexagonal wurtzite structure with a high preferential c-axis orientation. The surface
morphology showed a good uniformity with cracks and wrinkles. The transmittance decreased with thickness.
The bandgap energy was inversely varying with coating number. Photoluminescence spectra showed ultraviolet
with strong and weak blue and weak green emission peaks. Density functional theory and Hubbard (DFT + U)
method was then applied to study the structural, electronic, and optical properties of pure and 6.25% Mn-doped
ZnO materials. A decrease in bandgap energy from pure to 6.25% Mn-doped ZnO material was shown using the
DFT + U method. It also found that the Mn3d states were distributed far from Fermi level with a coexistence of
both ionic and covalent nature bonds. A slight shift toward the lower energy was noticed for optical properties by
Mn doping. The theoretical findings showed a similar behavior to those obtained by experiment.
Description
Keywords
Film thickness Sol-gel spin coating method Mn-doped ZnO Structural properties DFT+U