Estimation of Photovoltaic Performance of Dye Sensitized Solar Cell Using Self-Assembled Natural Dyes

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 (η). 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.