Triazine: An Important Building Block of Organic Materials for Solar Cell Application

Since the beginning of the 21st century, triazine-based molecules have been employed to construct different organic materials due to their unique optoelectronic properties. Among their applications, photovoltaics stands out because of the current need to develop efficient, economic, and green alternatives to energy generation based mainly on fossil fuels. Here, we review all the development of triazine-based organic materials for solar cell applications, including organic solar cells, dye-sensitized solar cells, and perovskite solar cells. Firstly, we attempt to illustrate the main synthetic routes to prepare triazine derivatives. Then, we introduce the main aspects associated with solar cells and their performance. Afterward, we discuss different works focused on the preparation, characterization, and evaluation of triazine derivatives in solar cells, distinguishing the type of photovoltaics and the role of the triazine-based material in their performance (e.g., as a donor, acceptor, hole-transporting material, electron-transporting material, among others). Throughout this review, the progress, drawbacks, and main issues of the performance of the mentioned solar cells are exposed and discussed. Finally, some conclusions and perspectives about this research topic are mentioned.

Synthesis and characterization of a conjugated porphyrin dyad entangled with carboxyl functionalized benzimidazolium: an efficient metal free sensitizer for DSSCs

Synthesis of a novel metal free porphyrin dyad with excellent electronic coupling and anti-aggregating stability via strong anchoring to semiconductor through six carboxyl groups exhibiting 6.9% PCE in a truly energy generating DSSC.

CoSe2/porous carbon shell composites as high-performance catalysts toward tri-iodide reduction in dye-sensitized solar cells

CoSe₂/carbon shell composites with many active sites were developed as catalysts for I₃⁻ reduction in dye-sensitized solar cells with efficiency and stability exceeding those of Pt.

Theoretical study on the effect of different π-linker on the performance of sensitizer in carbazole-based dyes

Derived from diarylamine sensitizer diphenyl-(7-pyridin-4-yl-9H-carbazol-2-yl)-amine (N13), a series of novel D[Formula: see text]A carbazole-based organic dye sensitizers with different [Formula: see text]-linkers were designed for searching more effective sensitizers in dye-sensitized solar cells (DSSCs) design. Optimized geometries, electronic structure, and other parameters, which can evaluate the performance of DSSCs effectively and intuitively, were theoretically calculated by density functional theory (DFT) and time-dependent DFT methods at the M06/6-31G(d,p) level. The results indicated that the maximum absorption wavelength of designed dye was red-shifted and the molar absorption coefficient ([Formula: see text]) became higher. This phenomenon can be explained by the modification of the [Formula: see text]-bridge. The simulated Ultraviolet–visible spectroscopy (UV-Vis) absorption spectrum showed that the designed N,N-diphenyl-7-(5-(7-(5-(pyridin-4-yl)thiophen-2-yl)benzo[c][1,2,5]thiadiazol-4-yl)thiophen-2-yl)-9H-carbazol-2-amine (N22) dye presents the largest red-shifted absorption band and the designed (E)-N,N-diphenyl-7-(2-(5[Formula: see text]-(pyridin-4-yl)-[2,2[Formula: see text]-bithiophene]-5-yl)vinyl)-9H-carbazol-2-amine (N21) dye showed the largest [Formula: see text], both of them depicted a high short-circuit photocurrent density ([Formula: see text]. Meanwhile, the charge separation hampered by long [Formula: see text]-linkers was also observed. These results are helpful for designing new sensitizers and providing effective guiding to experimental synthesis.

Enhanced performance of the dye-sensitized solar cells by the introduction of graphene oxide into the TiO2 photoanode

It is a potential way to enhance the performance of the DSSCs by constructing a GO-TiO₂ composited photoanode with graphene oxide.

Extended visible photosensitivity of carboxyethyltin functionalized polyoxometalates with common organic dyes enabling enhanced photoelectric performance

A kind of broad spectral responsive photoelectrode was assembled from carboxyethyltin–POM derivatives and organic dyes.

A triazine di(carboxy)porphyrin dyad versus a triazine di(carboxy)porphyrin triad for sensitizers in DSSCs

Two porphyrin-chromophores, i.e. triad PorZn-(PorCOOH)(2)-(piper)2 (GZ-T1) and dyad (PorZn)(2)-NMe2 (GZ-T1), have been synthesized and their photophysical and electrochemical properties have been investigated. The optical properties together with the appropriate electronic energy levels, i.e. the highest occupied molecular orbital (HOMO) and the lowest unoccupied molecular orbital (LUMO) energy levels, revealed that both porphyrin assemblies can function as sensitizers for dye sensitized solar cells (DSSCs). The and -based DSSCs have been prepared and studied using 20 mM CDCA as coadsorbent and were found to exhibit an overall power conversion efficiency (PCE) of 5.88% and 4.56%, respectively (under an illumination intensity of 100 mW cm(-2) with TiO(2) films of 12 μm). The higher PCE of the -sensitized DSSC, as revealed from the current-voltage characteristic under illumination and the incident photon to current conversion efficiency (IPCE) spectra of the two DSSCs, is mainly attributed to its enhanced short circuit current (J(sc)), although both the open circuit voltage (V(oc)) and the fill factor are improved too. The electrochemical impedance spectra (EIS) demonstrated a shorter electron transport time, longer electron lifetime and higher charge recombination resistance for the DSSC sensitized with the dye as well as a larger dye loading onto the TiO(2) surface.

Artificial hemes for DSSC and/or BHJ applications

In this review paper a summary of our studies is presented concerning the power conversion efficiency of DSSC and BHJ based on porphyrin hybrid materials.

A supramolecular assembling of zinc porphyrin with a π-conjugated oligo(phenylenevinylene) (oPPV) molecular wire for dye sensitized solar cell

A novel π-conjugated oligo(phenylenevinylene) (oPPV) (or LC) was prepared, as a new organic dye for dye-sensitized solar cells (DSSC), which contains a cyanoacrylic acid group on one end and a pyridyl group on the other.

A “click-chemistry” approach for the synthesis of porphyrin dyads as sensitizers for dye-sensitized solar cells

Two novel porphyrin dyads consisting of two zinc-metallated porphyrin units, linked by 1,2,3-triazole containing bridges, have been synthesized via “click” reactions, and used as sensitizers in DSSCs.

New solution processed bulk-heterojunction organic solar cells based on a triazine-bridged porphyrin dyad as electron donor

An unsymmetrical porphyrin dyad (ZnP)-[triazine-Npip]-(ZnPCOOH) consisting of two zinc-porphyrin units covalently linked to a peridine-containing triazine group has been used with PC₇₁BM as electron donor and acceptor, respectively, for the active layer of solution-processed BHJ organic solar cells.