25 research outputs found
Phthalocyanines and Porphyrinoid Analogues as Hole-and Electron-Transporting Materials for Perovskite Solar Cells
Organicâinorganic lead halide perovskite absorbers in combination with electron and hole transporting selective contacts result in power conversion efficiencies of over 23% under AM 1.5 sun conditions. The advantage of perovskite solar cells is their simple fabrication through solution-processing methods either in n-i-p or p-i-n configurations. Using TiO2 or SnO2 as an electron transporting layer, a compositionally engineered perovskite as an absorber layer, and Spiro-OMeTAD as a HTM, several groups have reported over 20% efficiency. Though perovskite solar cells reached comparable efficiency to that of crystalline silicon ones, their stability remains a bottleneck for commercialization partly due to the use of doped Spiro-OMeTAD. Several organic and inorganic hole transporting materials have been explored to increase the stability and power conversion efficiency of perovskite solar cells. IIn this review, we analyse the stability and efficiency of perovskite solar cells incorporating phthalocyanine and porphyrin macrocycles as hole- and electron transporting materials. The ÏâÏ stacking orientation of these macrocycles on the perovskite surface is important in facilitating a vertical charge transport, resulting in high power conversion efficiencyWe are grateful for the financial support of the MINECO, Spain
(CTQ2017-85393-P) and the Comunidad de Madrid (FOTOCARBON,
S2013/MIT-2841). IMDEA Nanociencia acknowledges support from
the âSevero Ochoaâ Programme for Centres of Excellence in R&D
(MINECO, Grant SEV-2016-0686). MKN thanks the EPFL and the
Swiss National Science Foundatio
Regioselective preparation of a bis-pyrazolinofullerene by a macrocyclization reaction
A single isomer of a pyrazolinofullerene bis-adduct was prepared
by tether-directed remote functionalization. Specifically, a
macrocyclization reaction between C60 and a bis-hydrazone reagent
has been carried out to generate a regioisomerically pure fullerene
bis-adduct which presents a lower LUMO than pristine C60
SynthÚse de systÚmes supramoléculaires photo-actifs combinant porphyrines et fullerÚnes
TOULOUSE3-BU Sciences (315552104) / SudocSudocFranceF
Meso-Substituted Porphyrins for Dye-Sensitized Solar Cells
Among the several approaches for harnessing solar energy and converting it into electricity, dye-sensitized solar cells (DSSC) represent one of the most promising methods for future large-scale power production from renewable energy sources. In these cells, the sensitizer is one of the key components harvesting solar radiation and converting it into electric current. The electrochemical, photophysical, and ground and excited state properties of the sensitizer play an important role for charge transfer dynamics at the semiconductor interface. Moreover, for long-term stability and practical applications, electrolytes based on the iodine/triiodine couple also suffer from two other disadvantages: the corrosive effect toward the metal electrodes, and the partial absorption of the visible light by triiodine anions. These issues hence constitute one of the reasons that have encouraged the development of alternative iodine-free redox couples in liquid electrolytes for DSSCs
Effect of Peripheral Substitution on the Performance of Subphthalocyanines in DSSCs
A series of six new subphthalocyanines (SubPcs) bearing an ethynylcarboxyphenyl anchoring unit and decorated with a variety of substituents at the peripheral position of the macrocycle have been synthesized in order to investigate the effect of the peripheral substituent on the performance of dye-sensitized solar cells
An Unsymmetrical, Push-Pull Porphyrazine for Dye-Sensitized Solar Cells
An unsymmetrical, push-pull porphyrazine derivative bearing an isoindole-4-carboxylic acid moiety (TT112) is synthesized and incorporated in a dye-sensitized solar cell (DSSC). The device, which constitutes the first example of a porphyrazine-sensitized solar cell, exhibits a maximum power conversion efficiency of 3.4 %
Electron transfer rates in an adsorbed C60-porphyrin dyad
International audienceAssociation of C60 and porphyrin entities to build light harvesting systems is a promising alternative for future photovoltaic devices. Herein, we determine the electron transfer rates in a C60-porphyrin dyad anchoredonto a gold ultramicroelectrode via the porphyrin core. Similar rates are observed for both redox entities, suggesting a tilt of the molecules allowing an efficient through-space communication between C60 and the electrod
Clustering in the simulated H α galaxy redshift survey from Nancy Grace Roman Space Telescope
A family of four pushâpull porphyrazines of A3B type, where each unit A contains two peripheral propyl chains and the unit B is endowed with a carboxylic acid, were prepared. The carboxylic acid was attached to the ÎČ-position of the pyrrolic unit, either directly (Pz 10), or through cyanovinyl (Pz 11) and phenyl (Pz 7) groups. The fourth Pz (14) consisted in a pyrazinoporphyrazine wherein the dinitrogenated heterocycle provided intrinsic donorâacceptor character to the macrocycle and contained a carboxyphenyl substituent. The direct attachment of the carboxylic acid functions and their linkers to the porphyrazine core produces stronger perturbation on the electronic properties of the macrocycle, with respect to their connection through fused benzene or pyrazine rings in TT112 and 14, respectively. The HOMO and LUMO energies of the Pzs, which were estimated with DFT calculations, show little variation within the series, except upon introduction of the cyanovinyl spacer, which produces a decrease in both frontier orbital energetic levels. This effective interaction of cyanovinyl substitution with the macrocycle is also evidenced in UV/Vis spectroscopy, where a large splitting of the Q-band indicates strong desymmetrization of the Pz. The performance of the four Pzs as photosensitizers in DSSCs were also investigated