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The spectral coverage of porphyrin-based light-harvesting arrays can be enhanced through the use of suitable accessory pigments. Perylene-monoimide dyes can serve as valuable accessory pigments with porphyrins. To investigate the choice of perylene-monoimide and the effects of molecular architecture on light-harvesting efficacy, five perylene-porphyrin dyads were prepared. Each dyad employs a diphenylethyne linker that bridges the perylene N-imide site and the porphyrin meso-position. Three dyads incorporate a mono-phenoxy perylene at the o-, m-, or p-position of the meso-aryl group on the porphyrin. The two remaining dyads incorporate a perylene-monoimide (bearing zero or three phenoxy substituents) at the p-position of the meso-aryl group on the porphyrin. The introduction of phenoxy groups on the perylenes increases the solubility, a key requirement for use in light-harvesting arrays. The long-wavelength absorption band of the perylene shifts from 506 nm to 532 or 533 nm upon substitution with one or three phenoxy groups, respectively. The synthesis of the dyads entails Pd-mediated coupling of a bromo-perylene and an ethynyl porphyrin, or the mixed-aldehyde condensation with a perylene-aldehyde, mesitaldehyde, and pyrrole. Five perylene-monoimide dyes bearing an ethyne or bromo substituent at the p-position of the N-aryl unit were developed for this modular chemistry. Each perylene-porphyrin dyad exhibits efficient energy transfer from the excited perylene to the ground-state porphyrin.

Soluble phthalocyanines, including organo-soluble tetrakis(2,9,16,23-tert-butylphthalocyanines) (M(TBPc), M = H₂, Cu, Mg; M(TBPc)₂, M = Tb, Dy) as well as the water-soluble sodium salt of sulfonated phthalocyanines ((MPc(SO₃Na)₄), M = Cu, Zn, Mg), and perylene tetracarboxylic derivatives (N,N'-bis(1,5-dimethylhexyl)-3,4: 9,10-perylenebis(dicarboximide)) have been prepared by microwave irradiation. Their photoelectric performances have also been investigated. Among lab-made cells, the SnO₂glass / MgPc(SO₃Na)₄ / PDHEP / Al photoelectric cell exhibits the best photoelectricity conversion effect with a short-circuit photocurrent (116.0 μA/cm²) under illumination of white light 1.201 mW/cm².

Five novel dyads, consisting of a tetraphenylporphyrine unit connected to a perylene monoimide diester unit via a flexible bridge -CONH-(CH${}_{\mathrm{\text{2}}}{)}_{\mathrm{\text{n}}}$- (n $=$ 4, 6, 8, 10 and 12), have been synthesized. Their structures were characterized by ${}^{\mathrm{\text{13}}}$C and ${}^{\mathrm{\text{1}}}$H nuclear magnetic resonance spectroscopy, infrared spectroscopy, mass spectrometry and elemental analysis. The UV-vis absorption spectra revealed these dyads have broad optical absorption in the ultraviolet and visible regions due to the complementary absorption of the two units. The differential scanning calorimetry traces and polarized optical microscopy textures showed all these dyads have columnar liquid crystal phases. Cyclic voltammetry revealed the highest occupied molecular orbitals of the dyads located on the porphyrin units, and the lowest unoccupied molecular orbitals located on the perylene units. In addition, these results were in agreement with that of the theoretical modeling. When excited at 423 or 473 nm, the photoluminescent emission spectra showed that the degree of fluorescence quenching of porphyrin units increased as the spacers became shorter. This quenching was ascribed to intramolecular photoinduced electron transfer, which also induced the dyad molecules to form the charge-separated states. The charge-separated molecules were further confirmed by the photocurrent response curves. These behaviors of broad absorption of the ultraviolet-visible light, yielding the charge-separated states of the molecules when excited and the formation of columnar liquid crystal phase made these dyads candidates for single-component photovoltaic active materials.

Hexa-peri-hexabenzocoronenes (HBCs), substituted by two different chromophores in an ortho arrangement, were synthesized for the first time and investigated towards their photophysical properties. Rylene-diimide dyes, in particular naphthalene-diimides (NDIs) and perylene-diimides (PDIs), were attached to the HBC as the first, and porphyrins as the second chromophore. Therefore, porphyrin-NDI-HPB as well as porphyrin-PDI-HPB precursors were accessed and converted into the respective HBC derivatives applying oxidative Scholl conditions. UV-vis absorption and fluorescence emission spectroscopy showed interesting photophysical behavior such as energy transfer processes. Particularly, the porphyrin-PDI-HBC displays pronounced absorption features between 330–650 nm, which cover a wide range of the visible spectrum.

Organic triplet-triplet annihilation photon upconversion (TTA-UC) systems have attracted considerable attention owing to their promising applicability in solar energy harvesting, optoelectronic devices, photocatalysts, and bio-imaging. In this study, a series of BODIPYs prepared by incorporating substituted/ unsubstituted arylselenium groups, 1 (R = H), 2 (R = OMe), and 3 (R = F), were evaluated as triplet photosensitizers for TTA-UC. Direct Se-C bond formation on the BODIPY core provided a facile intersystem crossing (ISC) channel from the excited singlet state to the metastable triplet state, being the most effective in 2, as inferred from the singlet oxygen generation experiments, possibly because of the n-electron arising from the OMe group. The UC behavior of systems comprising the sensitizers and perylene as the acceptor in deaerated toluene was investigated using a 524 nm-wavelength laser to detect upconverted emission at 449 nm; thus, the UC yield decreased in the order of 21% for 3 > 16% for 2 > 12% for 1. This trend is consistent with the Stern-Volmer constants calculated from the quenched triplet state lifetimes of the sensitizers as a function of the concentration of the perylene quencher. This suggests that the UC efficiency was mainly governed by the intermolecular triplet-triplet energy transfer (TTET) process between arylselanyl-BODIPY photosensitizers and the perylene acceptor. This result was rationalized by the efficient population of the long-lived triplet excited state of the sensitizer, which is advantageous for diffusion-controlled TTA-UC behavior.

Imide-based Subphthalocyanines (SubPcs) is gaining momentum as non-fullerene acceptors in organic solar cells (OSCs). Herein we report the synthesis, characterization, and photovoltaic performance of Perylenemonoimide (PMI)-SubPc conjugates in which the PMI is linked to the SubPc core by either alkynes or direct C-C bond. These derivatives are prepared via palladium-catalyzed cross-coupling reactions. The introduction of PMI units results in a red-shifted absorption, which can be described as the combination of the absorption properties of both SubPc and PMIs fragments. The absorption spectra are thus mainly composed of two transitions, one derived from the SubPc Q-band and the other from transitions within the PMI moieties. These PMI-SubPc systems exhibit moderate acceptor properties and therefore their use as non-fullerene acceptors in bulk-heterojunction organic solar cells is briefly explored.