N719 Derivatives for Application in a Dye-Sensitized Solar Cell (DSSC): A Theoretical Study

Geometry, reactivity descriptors, light harvesting efficiency, molecular radii, diffusion coefficient, and oxidation potential of RE(I)(CO)3Cl(TPA-2, 2'-bipyridine) in DSSC application: DFT/TDDFT study

Dye-sensitized solar cells (DSSCs) are an excellent alternative solar cell technology that is cost-effective and environmentally friendly. The geometry, reactivity descriptors, light-harvesting efficiency, molecular radii, diffusion coefficient, and excited oxidation state potential of the proposed complex were investigated. The calculations in this study were performed using DFT/TDDFT method with B3LYP functional employed on the Gaussian 09 software package. The calculations were used the 6-311 +  + G(d, p) basis set for the C, H, N, O, Cl atoms and the LANL2DZ basis set for the Re atom, with the B3LYP functional.. The balance of hole and electron in this complex has increased the efficiency and lifetime of DSSCs for photovoltaic cell applications. The investigated compound shows that the addition of the TPA substituent marginally changes the geometric structures of the 2, 2'-bipyridine ligand in the T1 state. As EDsubstituents were added to the compound, the energy gap widened and moved from ELUMO (- 2.904 eV) (substituted TPA) to ELUMO (- 3.122 eV) (unsubstituted). In the studying of solvent affects; when the polarity of the solvent decreases, red shifts appears in the lowest energy an absorption and emission band. Good light-harvesting efficiency, molecular radii, diffusion coefficient, excited state oxidation potential, emission quantum yield, and DSSC reorganization energy, the complex is well suited for use as an emitter in dye-sensitized solar cells. Among the investigated complexes mentioned in literature, the proposed complex was a suitable candidate for phosphorescent DSSC.

Emerging developments in dye-sensitized metal oxide photocatalysis: exploring the design, mechanisms, and organic synthesis applications

In the present day, the incorporation of environmentally conscious practices in the realm of photocatalysis holds a prominent position within the domain of organic synthesis. The imperative to tackle environmental issues linked to catalysts that cannot be recycled, generation of waste, byproducts, and challenges in achieving reaction selectivity during organic synthesis are more crucial than ever. One potential solution involves the integration of recyclable nanomaterials with light as a catalyst, offering the possibility of achieving sustainable and atom-efficient transformations in organic synthesis. Metal oxide nanoparticles exhibit activation capabilities under UV light, constituting a small percentage (4-8%) of sunlight. However, this method lacks sufficient environmental friendliness, and the issue of electron-hole recombination poses a significant hurdle. To tackle these challenges, multiple approaches have been proposed. This comprehensive review article focuses on the efficacy of dyes in enhancing the capabilities of heterogeneous photocatalysts, offering a promising avenue to overcome the constraints associated with metal oxides in their role as photocatalysts. The article delves into the intricate design aspects of dye-sensitized photocatalysts and sheds light on their mechanisms in facilitating organic transformations.

ZnO Nanowires/N719 Dye With Different Aspect Ratio as a Possible Photoelectrode for Dye-Sensitized Solar Cells

The vapor-liquid-solid (VLS) process was applied to fabricate zinc oxide nanowires (ZnO NWs) with a different aspect ratio (AR), morphological, and optical properties. The ZnO NWs were grown on a system that contains a quartz substrate with transparent conductive oxide (TCO) thin film followed by an Al-doped ZnO (AZO) seed layer; both films were grown by magnetron sputtering at room temperature. It was found that the ZnO NWs presented high crystalline quality and vertical orientation from different structural and morphological characterizations. Also, NWs showed a good density distribution of 69 NWs/μm² with a different AR that offers their capability to be used as possible photoelectrode (anode) in potential future device applications. The samples optical properties were studied using various techniques such as photoluminescence (PL), absorption, and transmittance before and after sensitization with N719 dye. The results demonstrated that NW with 30 nm diameter had the best characteristics as feasible photoelectrode (anode) (high absorption, minimum recombination, high crystallinity). Also, the present samples optical properties were found to be improved due to the existence of N719 dye and Au nanoparticles on the tip of NWs. NWs grown in this work can be used in different photonic and optoelectronic applications.

The influence of the shape and configuration of sensitizer molecules on the efficiency of DSSCs: a theoretical insight

The sensitizer is an active component of dye sensitized solar cell (DSSC) technology, which is highly influential for the performance of DSSCs. The present study attempts to investigate the relationship between the shape of the sensitizer molecule and efficiency of DSSCs. Specifically, 17 different structures were investigated, and classified into four categories based on the shape of the dye molecule, namely L-shaped (linear), V-shaped, X-shaped and Y-shaped, and into two different categories based on the donor moiety. The five of studied structures contained a triphenylamine (TPA) donor moiety, and twelve structures contained carbazole (CAR) donor moiety. Parameters related to the performance of DSSCs such as absorption spectra, intramolecular charge transfer indices, frontier molecular orbitals, light harvesting efficiency, excited-state lifetime, exciton binding energy, electrostatic potential, charge transfer and electron injection ability were studied using results obtained from electronic structure calculations. The analysis of these various parameters showed that the linear-shaped and V-shaped sensitizers possess better photon absorption ability, and the V-shaped structure is best suited shape for applications in high performance DSSCs.

Numerous studies have reported that the shape of a sensitizer matters for DSSC performance, while the present study investigates why and how it matters.

Density functional theory design of double donor dyes and electron transfer on dye/TiO2(101) composite systems for dye-sensitized solar cells

In this work, we designed a series of double donor organic dyes, named ME101-ME106, based on experimentally synthesized dye WD8, and further investigated their electronic structure, the stability of the dye/TiO₂ (101) systems, density of states (DOS) and absorption spectra using density functional theory (DFT) and time-dependent DFT (TDDFT). The molar extinction coefficients of all designed dyes are higher than WD8. It's fascinating that ME106 exhibits a smallest energy gap and 75 nm redshifts compared to WD8. The results of calculations reveal that ME101-ME106/TiO₂(101) surfaces are more stable than WD8, double donor dyes have sufficient electron injection driving force and have very strong transfer electron ability. It is expected that the design of double donors can provide a new understanding and guidance for the investigation of high efficiency dye-sensitized devices.

Cyclometalated Ru(ii) complexes with tunable redox and optical properties for dye-sensitized solar cells

Cyclometalated Ru(ii) complexes with 2-arylbenzimidazoles demonstrate enhanced light-harvesting properties and good characteristics in dye-sensitized solar cells.