The Golden Fig: A Plasmonic Effect Study of Organic-Based 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%).

Synthesis and Photophysics Characterization of Boronic Styril and Distyryl BODIPYs for Water-Based Dye-Sensitized Solar Cells

In this study, two boronic acid BODIPYs are obtained through a microwave-assisted Knoevenagel reaction. The aim is to use them for the first time as dyes in a photosensitized solar cell (DSSC) to mimic chlorophyll photosynthesis, harvesting solar light and converting it into electricity. The microwave-assisted Knoevenagel reaction is a straightforward approach to extending the molecular conjugation of the dye and is applied for the first time to synthesize BODIPY’s boronic acid derivatives. These derivatives have proved to be very useful for covalent deposition on titania. This work studies the photo-physical and electrochemical properties. Moreover, the photovoltaic performances of these two new dyes as sensitizers for DSSC are discussed. Experimental data show that both dyes exhibit photosensitizing activities in acetonitrile and water. In particular, in all the experiments, distyryl BODIPY was more efficient than styryl BODIPY. In this study, demonstrating the use of a natural component as a water-based electrolyte for boronic BODIPY sensitizers, we open new possibilities for the development of water-based solar cells.

Optically Transparent Gold Nanoparticles for DSSC Counter-Electrode: An Electrochemical Characterization

A gold nanoparticles transparent electrode was realized by chemical reduction. This work aims to compare the transparent gold nanoparticles electrode with a more commonly utilized gold-film-coated electrode in order to investigate its potential use as counter-electrode (CE) in dye-sensitized solar cells (DSSCs). A series of DSSC devices, utilizing I⁻/I³⁻ and Co(III)/(II) polypyridine redox mediators [Co(dtb)3]³⁺/²⁺; dtb = 4,4′ditert-butyl-2,2′-bipyridine)], were evaluated. The investigation focused firstly on the structural characterization of the deposited gold layers and then on the electrochemical study. The novelty of the work is the realization of a gold nanoparticles CE that reached 80% of average visible transmittance. We finally examined the performance of the transparent gold nanoparticles CE in DSSC devices. A maximum power conversion efficiency (PCE) of 4.56% was obtained with a commercial I⁻/I³⁻-based electrolyte, while a maximum 3.1% of PCE was obtained with the homemade Co-based electrolyte.

A Photoelectrochemical Study of Hybrid Organic and Donor—Acceptor Dyes as Sensitizers for Dye-Sensitized Solar Cells

An investigation on the photoelectrochemical and sensitizing properties of two different hybrid organic dyes, anchored as sensitizers on mesoporous TiO2, in Grätzel solar cells, is presented. Firstly, we studied the absorption properties of the C106 sensitizer, a Ru polypyridine complex, and of the Y123, an organic push and pull dye. In this work, we characterized these two dyes, employing two different electrolytes, with similar experimental condition and device parameters. From the J–V curves and IPCE photo action spectra, we performed an inedited bifacial study based on the comparison of their photovoltaic performances, exploiting several backgrounds (black or white). Among the obtained results from this study, we found the best bifaciality factor of 93% for C106 and the best power conversion efficiency of 12.8% for Y123. These results represent, concerning these two dyes and to the best of our knowledge, some of the highest values in literature.