Abstract:
In the present work, there are four main objectives to complete such as synthesis of Zinc oxide
(𝑍𝑛𝑂) nanoparticles, preparation of natural dyes, characterization of materials, fabrication of
device, the Dye-Sensitized Solar Cell (DSSC) and its photovoltaic performance by the solar
simulator. In this research, the sol-gel method is used for the synthesis of zinc oxide
nanoparticles. The thin films of prepared 𝑍𝑛𝑂 material is deposited on FTO glass. The self assembled natural dyes are extracted from beetroot and pomegranate. Natural dyes are used
rather than chemical-based dyes because of their low cost, great binding with the thin film of
semiconductors, different absorption ranges, etc. Various characterization techniques are being
used to analyze the prepared samples such as SEM, UV-Visible spectroscopy, FTIR, Raman
spectroscopy and Solar simulation to study the surface morphology, optical properties and
bonding of the samples. Scanning electron microscope (SEM) analyses showed the average
particles size of around 200 nm and larger. From energy dispersive x-ray spectroscopy (EDX)
analysis the elemental composition of sample is also found. The percentage composition of Zn
and O were 80.15 and 19.85 observed. Raman spectroscopy analysis presented the intensity,
band position and different modes of vibration. FTIR is an effective characterization technique
to confirm the absorption of surfactant molecule at the ZnO surface. The UV-visible
spectroscopy analysis showed the absorption spectra of self-assembled natural dyes
(pomegranate) at wavelength 526.13 nm and the absorption peak is of 1.138 while for beetroot
dye there were two peaks found at wavelengths 481.2 nm & 527.5nm having absorbance 1.02
& 1.03 respectively. The band gap of 𝑍𝑛𝑂 nanoparticles was found to be 3.20 eV. The working
electrode was fabricated that based on the thin film of 𝑍𝑛𝑂 nanoparticles and natural dyes
(pomegranate and beetroot). Solar simulation was performed to estimate the device
performance, having light energy 1000 𝑚𝑊/𝑐𝑚2
, to measure the photovoltaic parameters of
DSSC such as the short circuit current density (𝐽𝑠𝑐), open-circuit voltage (𝑉𝑜𝑐), fill factor (𝐹𝐹)
and efficiency (Ξ·). The efficiency of pomegranate and beetroot natural dyes with ZnO based
DSSC was 1.0823%, and 0.81489%. It is determined that the efficiency in case of
pomegranate-based dye-sensitized solar cell has greater efficiency values than beetroot dye.
This result showed that natural dyes are more suitable rather than use of commercial based
dyes for the construction of dye-sensitized solar cell.
