Electronic and optical properties’ tuning of phenoxazine-based D-A2-π-A1 organic dyes for dye-sensitized solar cells. DFT/TDDFT investigations

Abstract

Modulation of molecular features of metal free organic dyes is important to present sensitizers with competing electronic and optical properties for dye sensitized solar cells (DSSCs). The D-A 2 -π-A 1 molecular design based on phenothiazine skeleton (D) connected with benzothiadiazole (A 2 ) linked with furan π-spacer and acceptor unit of cynoacrylic acid (A 1 ) were fabricated and examined theoretically for possible use as DSSCs. Density functional theory (DFT) and time dependent density functional theory TDDFT were used to study the effect of additional donors on the photophysical properties of the dyes. Eight (8) different donor subunits were introduced at C7 of phenoxazine based dye skeleton to extend the π-conjugation, lower HOMO-LUMO gap (E g ) and improve photo-current efficiency of the dye sensitizer. All the dye sensitizers (except P3 and P4) exhibited capability of injecting electrons into the conduction band of the semiconductor (TiO 2 ) and regenerated via redox potential (I − /I 3 - ) electrode. Attachment of 2-hexylthiophene (P2) remarkably lowered the E g , extended π-electron delocalization, hence, gives higher absorption wavelength (λ max ) at 752 nm. The donor subunit containing 2-hexylthiophene (P2) presented the best chemical hardness, open circuit voltage (V oc ), and other comparable electronic properties, making P2 the best DSSC candidate amongst the optimized dyes. The reported dyes would be interesting for further experimental research.

Solubility Measurement and Modeling of 9-Phenylcarbazole in Various Organic Solvents at Different Temperatures toward Efficient Process Design of Solvent Antisolvent Precipitation

“…A carbazole skeleton with a π-electron conjugated system, intramolecular electron transfer characteristics, and freely matched lone pair electrons on the nitrogen atom has been a key structural motif of a variety of optoelectronic and biologically active compounds. − In particular, 9-phenylcarbazole (PCz) with the molecular formula C 18 H 13 N, also known as N -phenylcarbazole, has been one of the most widely used organic materials in the synthesis of functional molecules for organic light-emitting diodes (OLEDs) and optical sensing agents. − Besides, carbazole derivatives exhibit antiproliferative activities, including the arrest of the cell cycle and the induction of apoptosis; it is also a kind of an important intermediate for pharmaceuticals and pesticides . The crystals of PCz obtained by the solution growth technique have also been demonstrated as organic single crystal scintillators in existence for a multitude of applications including homeland security, nuclear non-proliferation, nuclear physics, and non-destructive testing. , The purity of PCz in raw materials is a key index during the product engineering, and in practical industrial production process, the PCz materials can be purified by simple solvent antisolvent recrystallization.…”

The Impact of TPA Auxiliary Donor and the π-Linkers on the Performance of Newly Designed Dye-Sensitized Solar Cells: Computational Investigation

“…In this interest, the search for an efficient method for harnessing solar light conversion to electricity using dyes-sensitized solar cells (DSSCs) has been investigated [ 1 , 2 , 3 , 4 , 5 , 6 , 7 ]. The solution-processable photovoltaic DSSCs have the advantages of being clean, cheap, renewable, inexhaustible, pollution-free, and large-scale production [ 8 , 9 , 10 , 11 , 12 , 13 , 14 ]. Because of their lower production cost, DSSCs offer a viable alternative to conventional all-inorganic solar cells.…”

Diseño de electrodonadores basados en diciclopentapirrol que permiten una alta fotoconversión en celdas solares orgánicas

“…La teoría del funcional de la densidad (DFT) y la teoría del funcional de la densidad dependiente del tiempo (TD-DFT) se han usado ampliamente para investigar, diseñar, evaluar y predecir propiedades ópticas, electrónicas y fotovoltaicas en sistemas captadores de luz a nivel molecular con un bajo costo computacional (Wang et al, 2014;Tai et al, 2015;El Alamy et al, 2017;Chen et al, 2019;Li & Zheng, 2019;Afolabi et al, 2021). Por tal razón, muchos investigadores sugieren que los métodos de química cuántica podrían ilustrarnos moléculas electrodonadoras eficientes y proporcionar una ayuda preliminar para comprender como la estructura molecular y sus propiedades afectan el rendimiento del dispositivo fotovoltaico, minimizando costos y ahorrando esfuerzos de síntesis (Wang et al, 2014).…”