Perfluorinated Subphthalocyanine as a New Acceptor Material in a Small‐Molecule Bilayer Organic Solar Cell

Abstract

The complex refractive index of fluorinated subphthalocyanines (SubPcs) deposited by vacuum sublimation is determined by spectral ellipsometry. Their performance as acceptor material is characterized in a range of donor/acceptor heterojunctions in organic photovoltaic cells (OPVCs) by current–voltage measurements under 1 sun AM 1.5D simulated solar illumination and spectral response. Both electron and hole transfer between donor and acceptor materials is demonstrated. Power conversion efficiencies of 0.96% are found with an open‐circuit bias of 940 mV. Hence, it is shown that fluorinated SubPcs can be considered as an acceptor material in OPVCs with an absorption in the visible comparable to that of well‐known metallophthalocyanines.

8.4% efficient fullerene-free organic solar cells exploiting long-range exciton energy transfer

“…Alternatives to fullerenes for vacuum-deposited small-molecule organic solar cells mainly comprise perylene derivatives 4 or halogenated (sub-) phthalocyanines [16][17][18] . However, these non-fullerene acceptors rarely show improved performance over their fullerene counterparts.…”

Synthesis of Meso‐Substituted Subphthalocyanine–Subporphyrin Hybrids: Boron Subtribenzodiazaporphyrins

“…The selection of a boronate ester template leads to control over the apical substituent (13,(15)(16)(17). Most significant, however, is the ability to engineer the new "meso" substituents at willsynthetic control that makes this new class of hybrid structures uniquely attractive.…”

“…[7] The optical properties of SubPcs are distinctive as they show intense absorption and emission around 550 nm, leading to a particular focus on their application as components in photovoltaic cells. [7,[11][12][13] A small number of subporphyrins are also known, the most notable examples being the synthetic breakthroughs reported by Osuka and Kobayashi leading to the first syntheses of boron tribenzosubporphyrins 5 [14] and 6 [15] ( Figure 2). The most challenging core modification of the oligopyrrole/indole macrocycles is arguably the generation of hybrid structures [16] that lie between the classic porphyrin and phthalocyanine parent structures.…”

An overview of molecular acceptors for organic solar cells

“…A series of fluorinated boron subphthalocyanines used as acceptors in bilayer OSC devices were associated with phthalocyanine-based donors leading to PCE close to 1% [39]. Small molecular acceptors combining the highly electron deficient 2-vinyl-4,5-dicyanoimidazole moiety named Vinazene and benzothiadiazole were developed as processable oligomers for photovoltaics applications [40].…”