Lighting porphyrins and phthalocyanines for molecular photovoltaics

Abstract

The field of organic photovoltaics (OPV) represents one of the most promising technological areas. Porphyrins and phthalocyanines are perfectly suited for their integration in light energy conversion systems. These colored macrocycles exhibit very attractive physical properties, particularly very high extinction coefficients in the visible and near IR regions, where the maximum of the solar photon flux occurs, that is necessary for efficient photon harvesting, besides a rich redox chemistry, as well as photoinduced electron transfer and semiconducting capabilities.

Charge recombination losses in thiophene-substituted porphyrin dye-sensitized solar cells

“…In this type of solar cell the properties of the dye, such as colour, molecular extinction coeffi-cient and robustness under illumination, are of utmost importance. Among the examples of dyes published in the literature [3] for Gratzel€ solar cells, porphyrins [4] have pleasant colours [5], excel-lent molecular extinction coefficients [6,7] and good robustness [8,9]. Moreover, based on the work of Yella and co-workers [1], efficiencies that surpass the values obtained with ruthenium sen-sitizers have been achieved.…”

Dendrimer porphyrin-based self-assembled nano-devices for biomedical applications

“…20,21 Because porphyrin and phthalocyanine have unique photofunctional properties, such as a large absorption cross-section, fluorescence emission, and photosensitizing properties, DP and DPc can be used as photofunctional nano-devices. [22][23][24][25] Upon excitation by light, porphyrin and phthalocyanine can fluoresce or transfer their excitation energy or an electron to an appropriate acceptor molecule. 25 This unique property makes these molecules useful for probing micro-environments or as photosensitizers for photodynamic therapy (PDT).…”

“…[22][23][24][25] Upon excitation by light, porphyrin and phthalocyanine can fluoresce or transfer their excitation energy or an electron to an appropriate acceptor molecule. 25 This unique property makes these molecules useful for probing micro-environments or as photosensitizers for photodynamic therapy (PDT). [26][27][28][29] However, because porphyrin and phthalocyanine are strongly hydrophobic and because they have a large p conjugation domain, they often form aggregates.…”

Integrating metalloporphycenes into p-type NiO-based dye-sensitized solar cells

“…Diverse organic or inorganic chromophores have recently been tested in both types of DSSCs. [5][6][7][8] Fine tuning synthetic parameters such as the metalation of the chromophore, the nature of the anchor, and the bridge that links the chromophore to the anchor, have made control over important characteristics like highly effective charge separation, reduced charge recombination, and long term stability possible. [9][10][11][12] Semiconductor nickel oxide (NiO) stands out as an electrode material for p-type DSSCs.…”

“…13 We have focused on porphycenes because of their similarity to porphyrins and phthalocyanines. 16,17 In contrast to the electrondonating features of porphyrins and phthalocyanines, which are widely used in n-type DSSCs, 8,18 porphycenes are strong electron acceptors, making them more suitable building blocks for p-type DSSCs. Only a few examples of the use of free-base porphycenes in solar energy devices are known to date.…”