Photophysical, Electrochemical and Photovoltaic Properties of Porphyrin-Based Dye Sensitized Solar Cell

Abstract

Porphyrins occur in a number of important biomolecules and are also synthetically made for use as probe component of chemical and biological sensors. The performance of dye sensitized solar cells with two different porphyrin dyes was investigated in this work. The two porphyrin complexes comprised of a metal-free 5, 10, 15, 20-meso-tetrakis-(9H-2-fluorene-yl) porphyrin (H 2 TFP) and its Zinc complex (ZnTFP). UV-Vis, Fluorescence, and Fourier transformed infrared measurements of the two dyes were carried out to evaluate their absorption, emission and binding characteristics. Both dyes absorbed light in the UV-visible region all the way to the near-infrared. The surface morphology and elemental analysis of the porphyrin dye sensitized photoanodes were determined using Field Emission Scanning Electron Microscopy Imaging and Transmission Electron Microscopy Imaging. Cyclic voltammetry studies, current-voltage characteristics and the electrochemical impedance spectroscopic studies were also carried out. Solar-to-electric energy efficiency of H 2 TFP dye sensitized solar cell was higher (0.11%) than that of the zinc complex (0.08%). Thus the metal free porphyrin generated more power than the zinc complex under similar conditions. The impedance measurement also displayed less overall resistance for the free porphyrin (50 Ω) compared with the zinc complex (130 Ω). The LUMO levels of H 2 TFP and ZnTFP sensitizers were −0.87 eV and −0.77 eV respectively. Both of these LUMO values are higher than the lower bound level of the conduction band of TiO 2 (−4.0 eV), ensuring the efficient injection of an electron from the excited porphyrin dye to the conduction band of the titanium dioxide.

Cosensitization in Dye-Sensitized Solar Cells

“…Various imaging techniques with nanometer resolution complement these spectroscopy methods by enabling the analysis of dye···TiO 2 surface structure at the molecular scale. For example, scanning electron microscopy (SEM), together with energy-dispersive X-ray analysis (EDX), has been used to confirm dye adsorption onto TiO 2 , while high-resolution transmission electron microscopy (TEM) has been employed to locate the dyes on the TiO 2 surface . Electron microscopy is often complemented by elemental analysis using an electron-probe microanalyzer (EPMA); to this end, the microscopic distribution of two cosensitizer dyes within a cross-section TiO 2 profile of a DSC working electrode has been determined .…”

“…For example, scanning electron microscopy (SEM), together with energy-dispersive X-ray analysis (EDX), has been used to confirm dye adsorption onto TiO 2 , while high-resolution transmission electron microscopy (TEM) has been employed to locate the dyes on the TiO 2 surface. 101 Electron microscopy is often complemented by elemental analysis using an electronprobe microanalyzer (EPMA); to this end, the microscopic distribution of two cosensitizer dyes within a cross-section TiO 2 profile of a DSC working electrode has been determined. 102 Meanwhile, atomic force microscopy (AFM) has been used to image the mechanism by which aggregation of ruthenium-based dyes builds up during the early stages of dye•••TiO 2 adsorption.…”

Synthesis, Characterization, and Studies on Photophysical Properties of Rhodamine Derivatives and Metal Complexes in Dye-Sensitized Solar Cells

“…Different types of dye have been utilized in the fabrication of dye-sensitized solar cells with varying percentages of solar power-to-electric power efficiencies. These dyes include ruthenium-based dyes, − prophyrins, − cyanines, − natural dyes, − and other synthetic dyes. − Rhodamine dyes are fluorescent dyes, which are soluble in many solvents and could be used in the fabrication of dye-sensitized solar cells …”

Photophysical Studies of Ruthenium-Based Complexes and the Performance of Nanostructured TiO2 Based Dye Sensitized Solar Cells

“…Dyes that have been synthesized and applied in DSSCs include ruthenium complexes, [22,23] Porphyrin dyes, [24] and Cyanine dyes [25]. Among these groups, DSSCs using ruthenium complex dyes have consistently produced the best results due to their relatively long life in metal-to-ligand charge transfer (MLCT) properties.…”