Porphyrinic Materials: Self-Assembly on Surfaces

Zirconium(IV) and Hafnium(IV) Porphyrin and Phthalocyanine Complexes as New Dyes for Solar Cell Devices

“…19,77 Similarly, chlorins, isobacteriochlorins, and bacteriochlorins have red-shifted Soret bands and stronger Q bands than TPP, 23,95 or multichomophore arrays wherein the attaching moiety is the Zr complex. 13,15,19,21,96 Though designed porphyrins and phthalocyanines that are made in low synthetic yields can have better performance, we focus on commercial viable dye systems that can be made in good yields using green chemistry and click-type reactions to append exocyclic motifs. 97,98 Addition of cooadsorbants to the system, which are reported to suppress aggregation of porphyrinoid dyes and to reduce back electron transfer, 87,99 may improve the performance as well.…”

“…The increased absorption of blue light is offset by the decreased absorption of red light where there are more photons to be captured. Since the λ max of Pc can be tuned from about 650 to 830 nm and the complexes can be blended into effective solar cell devices, one strategy to improve this dye system may be to use a series of (Pc)Zr (II) . , Similarly, chlorins, isobacteriochlorins, and bacteriochlorins have red-shifted Soret bands and stronger Q bands than TPP, , or multichomophore arrays wherein the attaching moiety is the Zr complex. ,,,, Though designed porphyrins and phthalocyanines that are made in low synthetic yields can have better performance, we focus on commercial viable dye systems that can be made in good yields using green chemistry and click-type reactions to append exocyclic motifs. , Addition of coadsorbants to the system, which are reported to suppress aggregation of porphyrinoid dyes and to reduce back electron transfer, , may improve the performance as well.…”

“…The diverse photophysical and chemical properties of porphyrinoids can be tuned by metalation with almost any metal ion and/or exocyclic modification of the macrocycle to adjust excited state lifetimes, HOMO–LUMO energies, optical-cross section, and redox potentials. − Simple Por and Pc, such as those described herein, can be commercially viable dyes for solar energy applications because they can be synthesized in good yields from simple starting materials . Functional supramolecular materials composed of porphyrinoids can be robust, and are useful in artificial photosynthesis in terms of light harvesting and for understanding energy and electron transfer between dyes. − Pcs are excellent candidates for solar light collection because they have strong Q bands in the red to near-IR (630–780 nm) region , where the Pors have weaker absorption bands (Figure ). The low solubility of Pc presents challenges since aggregates can have diminished effectiveness in these applications, but peripheral substitution can simultaneously improve solubility and change the HOMO–LUMO energy gap, thereby the electronic absorption spectra. , Since porphyrins have strong B band absorptions in the blue and Pc have strong Q absorptions in the red, they can be used in combination in thin film materials to broaden absorptivity compared to a single dye …”