Ag ion implanted TiO2 photoanodes for fabrication of highly efficient and economical plasmonic dye sensitized solar cells

Green Synthesis of Pristine and Ag-Doped TiO2 and Investigation of Their Performance as Photoanodes in Dye-Sensitized Solar Cells

Dye-sensitized solar cells (DSSCs) have emerged as a potential candidate for third-generation thin film solar energy conversion systems because of their outstanding optoelectronic properties, cost-effectiveness, environmental friendliness, and easy manufacturing process. The electron transport layer is one of the most essential components in DSSCs since it plays a crucial role in the device's greatest performance. Silver ions as a dopant have drawn attention in DSSC device applications because of their stability under ambient conditions, decreased charge recombination, increased efficient charge transfer, and optical, structural, and electrochemical properties. Because of these concepts, herein, we report the synthesis of pristine TiO2 using a novel green modified solvothermal simplistic method. Additionally, the prepared semiconductor nanomaterials, Ag-doped TiO2 with percentages of 1, 2, 3, and 4%, were used as photoanodes to enhance the device's performance. The obtained nanomaterials were characterized using XRD, FTIR, FE-SEM, EDS, and UV-vis techniques. The average crystallite size for pristine TiO2 and Ag-doped TiO2 with percentages of 1, 2, 3, and 4% was found to be 13 nm by using the highest intensity peaks in the XRD spectra. The Ag-doped TiO2 nanomaterials exhibited excellent photovoltaic activity as compared to pristine TiO2. The incorporation of Ag could assist in successful charge transport and minimize the charge recombination process. The DSSCs showed a Jsc of 8.336 mA/cm2, a Voc of 698 mV, and an FF of 0.422 with a power conversion efficiency (PCE) of 2.45% at a Ag concentration of 4% under illumination of 100 mW/cm2 power with N719 dye, indicating an important improvement when compared to 2% Ag-doped (PCE of 0.97%) and pristine TiO2 (PCE of 0.62%).

Enhanced Photocatalytic and Photokilling Activities of Cu-Doped TiO2 Nanoparticles

In this work, metal-doped titanium dioxide (TiO₂) was synthesised with the aim of improving photocatalytic degradation and antimicrobial activities; TiO₂ was doped with copper (Cu) ranging from 0.1 to 1.0 wt%. The physical and chemical properties of the Cu-doped TiO₂ nanoparticles were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), the Brunauer–Emmett–Teller method (BET) and diffuse reflection spectroscopy (DRS). The results revealed that the anatase phase of TiO₂ was maintained well in all the Cu-doped TiO₂ samples. No significant difference in the particle sizes or the specific surface areas was caused by increasing Cu doping. However, the band gap decreased continuously from 3.20 eV for undoped TiO₂ to 3.12 eV for 1.0 wt.% Cu-doped TiO₂. In addition, the 0.1 wt.% Cu-doped TiO₂ displayed a much greater photocatalytic degradation of methylene blue (MB) and excellent antibacterial ability for Escherichia coli (E. coli) compared to undoped TiO₂. On the other hand, the high Cu doping levels had negative impacts on the surface charge of nanoparticles and charge transfer for OH• generation, resulting in decreasing MB degradation and E. coli photokilling for 1.0 wt.% Cu-doped TiO₂.

Bimetallic Implanted Plasmonic Photoanodes for TiO2 Sensitized Third Generation Solar Cells

An auspicious way to enhance the power conversion efficiency (PCE) of third generation sensitized solar cells is to improve the light harvesting ability of TiO2 sensitizer and inhibition of back recombination reactions. In the present work, we have simultaneously comprehended both the factors using stable bimetallic Au and Ag metal nanoparticles (Mnps) embedded in TiO2 with ion implantation technique at lower fluence range; and explored them in third generation dye sensitized solar cells (DSSCs). The best performing Au-Ag implanted DSSC (Fluence- 6 × 1015 ions cm-2) revealed 87.97% enhancement in its PCE relative to unimplanted DSSC; due to plasmon induced optical and electrical effects of Mnps. Here, optimized bimetallic Au-Ag Mnps embedded in TiO2 improves light harvesting of N719 dye; due to the well matched localized surface plasmon resonance (LSPR) absorption band of Au and Ag with low and high energy absorption bands of N719 dye molecules, respectively. Furthermore, Au and Ag acts as charge separation centers in TiO2 that inhibit the recombination reactions occurring at photoanode/electrolyte interface via prolonging photo-generated electron lifetime; resulting in efficient inter-facial charge transportation in DSSCs.