Effect of thienyl units in cyanoacrylic acid derivatives toward dye-sensitized solar cells

• Published in: Journal of photochemistry and photobiology. B, Biology Vol. 197; p. 111555
• Main Authors: Kula, Sławomir, Szlapa-Kula, Agata, Fabiańczyk, Aleksandra, Gnida, Paweł, Libera, Marcin, Bujak, Karolina, Siwy, Mariola, Schab-Balcerzak, Ewa
• Format: Journal Article
• Language: English
• Published: Switzerland Elsevier B.V 01.08.2019; Elsevier BV
• Subjects: Acids; Atomic force microscopy; Chemical analysis; Chemical compounds; Coloring Agents - chemistry; Cyanoacrylates - chemical synthesis; Cyanoacrylates - chemistry; Cyanoacrylic acid derivatives; Density Functional Theory; Dye-sensitized solar cells; Dye-sensitized solar cells (DSSCs); Dyes; Electric Power Supplies; Electrochemistry; Electron affinity; Energy conversion efficiency; Energy gap; Infrared analysis; Ionization; Ionization potentials; Knoevenagel condensation; Microscopy; Microscopy, Atomic Force; Molecular orbitals; Molecular structure; Morphology; NMR; Nuclear magnetic resonance; Optical properties; Organic chemistry; Oxidation-Reduction; Photovoltaic cells; Photovoltaics; Solar cells; Solar Energy; Submerging; Thermal decomposition; Thiophene derivatives; Titanium - chemistry; Titanium dioxide; Thiophene derivatives; Dye-sensitized solar cells (DSSCs); Cyanoacrylic acid derivatives; Knoevenagel condensation
• DOI: 10.1016/j.jphotobiol.2019.111555
• ISSN: 1011-1344

A series of heterocyclic donor-acceptor systems were synthesized and well characterized by using 1H, 13C NMR, FT-IR, and elemental analysis. They were designed to investigate the effect of thiophene and cyanoacrylic acid number units on the thermal, optical, electrochemical and finally photovoltaic properties of dye-sensitized solar cells prepared with the selected compounds. The effect of chemical structure on their properties was demonstrated. They showed the beginning of thermal decomposition between 230 and 270 °C. The compounds absorbed the radiation in the range of 300–500 nm or 200–400 nm. They were electrochemically active and varied in energy band gap from 3.40 to 1.58 eV. Additionally, their optimized geometry, HOMO–LUMO levels, ionization potential, and electron affinity were evaluated using density functional theory. The photovoltaic devices based on TiO2 sensitized with the obtained molecules exhibited low power conversion efficiency, which was the highest for the device containing the symmetrical molecule with bithiophene structure. Under co-sensitization, the cell made of the same compound gave significant enhancement of efficiency of 6.3% being higher to that of the individual device prepared from dye N719 (5.75%). Moreover, the effects of immersion time of TiO2 electrode in the dye solution and co-sensitization methods were tested. The surface morphology of photoanode was investigated using atomic force microscopy. [Display omitted] •A series of cyanoacrylic acid derivatives with thienyl units were synthesized.•The effect of chemical structure on their properties was demonstrated.•The selected compounds were tested in dye-sensitized solar cells.•The highest PCE exhibited cell with symmetrical molecule contains bithiophene core.•Co-sensitization enhanced efficiency to 6.3% being higher than with a neat N719.