Phthalocyanines and Subphthalocyanines: Perfect Partners for Fullerenes and Carbon Nanotubes in Molecular Photovoltaics

Abstract

The huge interest towards fullerenes and carbon nanotubes in molecular materials and materials science is closely related to the intriguing properties of these carbon nanostructures such as their excellent electrical conductivity and remarkable chemical stability, among others. In this connection, organic photovoltaics (OPVs) is one of the research fields where these carbon allotropes have been extensively employed, mainly as electron‐accepting materials. Among the electron‐donating counterparts, phthalocyanines (Pcs) and subphthalocyanines (SubPcs) are some organic compounds largely used for this pourpose mainly due to their intense light‐harvesting ability in the red and near infrared region of the solar spectrum, and rich and tuneable redox chemistry. In this review, we summarize some of the most recent and relevant achievements in the preparation of fullerene‐ and carbon nanotube‐based OPVs containing Pcs and/or SubPcs, paying a special attention to the effect that i) the structural and electronic modifications of the Pc and SubPc derivatives, ii) the different type of OPV architecture, and iii) the preparation method, have on the performance of the OPV devices. A section of this review has been also devoted to the used of SubPcs as electron‐accepting materials in fullerene‐free PV cells highlighting the great potential of these class of materials for the preparation of efficient organic solar cells.

Boron Subphthalocyanines and Silicon Phthalocyanines for Use as Active Materials in Organic Photovoltaics

“…When BsubPcs first appeared in OPVs they were exclusively applied as electron donating materials paired with C 60 fullerene . The vast amount of research and progress made towards advancing the application of BsubPcs as electron donors was recently reviewed by Torres et al . With BsubPcs well‐established in the electron donor space, recent efforts have been more focused on using BsubPcs to replace fullerene as electron acceptors.…”

Graphene and Carbon‐Nanotube Nanohybrids Covalently Functionalized by Porphyrins and Phthalocyanines for Optoelectronic Properties

“…Chemical functionalization can potentially pave the way to the use of graphene and CNTs in real‐world applications. In most cases, when organic chromophores are covalently attached to graphene/CNTs, their extended aromatic character is perturbed, enabling the control of modulating their optoelectronic properties . In addition, the covalent functionalization affords the opportunity to improve the solubility and processability of graphene/CNTs.…”

Distance Matters: Effect of the Spacer Length on the Photophysical Properties of Multimodular Perylenediimide–Silicon Phthalocyanine–Fullerene Triads

“…[9,10] There are av ariety of chemically stable building blocks, easy to synthesize and functionalize and, therefore, with tunable light harvesting and photophysical properties, suitable to "construct" high-performance artificial photosynthetic systems. Among the availableb uilding blocks, perylenediimides (PDI), [11][12][13] phthalocyanines (Pcs) [14][15][16] and C 60 -fullerene [17,18] stand up. PDI and Pcs exhibit large molare xtinction coefficients, up to 10 5 m À1 cm À1 ,w ith absorption and emission spectra covering the 400-800nmr egion.T hey also present genuine electron-acceptora nd electron-donor characters, respectively,w hich can be modulated through chemicalm odifications.O nt he other hand, C 60 -fullerene is aw ell-known electron-acceptorm oiety,d ue to its large p-electron 3D spherical system, which makes it to presentasmall reorganization energya fter reduction, which resultsi nf ast charges eparation process and slow recombination of the formed charged separated state.…”