A fully electronically conjugated phthalocyanine–perylenemonoimidebenzimidazole system has been synthesized, in which the conjugation goes through the imide position of the perylene.

The functionalization of MoS2 is of paramount importance for tailoring its properties towards optoelectronic applications and unlocking its full potential. Zinc phthalocyanine (ZnPc) carrying an 1,2‐dithiolane oxide linker was used to functionalize MoS2 at defect sites located at the edges. The structure of ZnPc‐MoS2 was fully assessed by complementary spectroscopic, thermal, and microscopy imaging techniques. An energy‐level diagram visualizing different photochemical events in ZnPc‐MoS2 was established and revealed a bidirectional electron transfer leading to a charge separated state ZnPc.+‐MoS2.−. Markedly, evidence of the charge transfer in the hybrid material was demonstrated using fluorescence spectroelectrochemistry. Systematic studies performed by femtosecond transient absorption revealed the involvement of excitons generated in MoS2 in promoting the charge transfer, while the transfer was also possible when ZnPc was excited, signifying their potential in light‐energy‐harvesting devices.

A new ZnPc-PDI dyad presenting for the first time a charge-separated state lower in energy than the triplet excited state of the ZnPc and PDI has been synthesized. The rational design implies the substitution of the ZnPc with phenoxy groups and the bay substitution of the PDI with sulfonyl substituents. The lifetime of the charge-separated state was 72 μs.

The functionalization of MoS 2 is of paramount importance for tailoring its properties towards optoelectronic applications and unlocking its full potential. Zinc phthalocyanine (ZnPc) carrying an 1,2-dithiolane oxide linker was used to functionalize MoS 2 at defect sites located at the edges.T he structure of ZnPc-MoS 2 was fully assessed by complementary spectroscopic,t hermal, and microscopyi maging techniques. An energy-level diagram visualizing different photochemical events in ZnPc-MoS 2 was established and revealed ab idirectional electron transfer leading to ac harge separated state ZnPcC + -MoS 2 C À .M arkedly,e vidence of the charge transfer in the hybrid material was demonstrated using fluorescence spectroelectrochemistry.Systematic studies performed by femtosecond transient absorption revealed the involvement of excitons generated in MoS 2 in promoting the charge transfer, while the transfer was also possible when ZnPc was excited, signifying their potential in light-energy-harvesting devices.

Abstract.Here, we report a new procedure for the co-sensitization with quantum dots (QDs) and dyes for sensitized solar cell. Cascade co-sensitization of TiO 2 electrodes are obtained by the sensitization with CdS quantum dots (QDs) and zinc phthalocyanines (ZnPcs), in which ZnPcs containing sulfur atom have been specially designed to produce a cascade injection by attaching directly to QDs. This strategy causes a double synergetic interaction. This is the differentiating point of cascade co-sensitization in comparison with other approach in which dyes with conventional functionalization are employed, that pursue anchoring dyes to TiO 2 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 I ntroductionAn elegant strategy to improve the light-harvesting in photovoltaic devices is to use complementary light harvesters capable to produce panchromatic absorption. Here we have combined semiconductor quantum dots (QDs) and ad hoc designed phthalocyanines (Pcs) in order to prepare sensitized solar cells with enhanced efficiency. QDs are among potential key players in the next generation of photovoltaic devices [1] due to their low-cost solution-phase processability, large absorption cross sections, a spectrally tunable absorption onset (achieved via the quantum size effect), and enhanced multiple exciton generation or carrier multiplication. [2] After the first report on a certified QD solar cell, [3] a remarkable progress has been reached just in a couple of years obtaining certified power conversion efficiencies (PCEs) approaching 9%. [4] 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 3 On the other hand, Pcs are outstanding dye candidates in dye sensitized solar cells (DSSCs) due to their high extinction coefficient in the infrared spectral region and to their high thermal and chemical stabilities. [5] Pcs incorporated in DSSCs have achieved PCEs as high as 6.4 %, [6] still far away from the 12.75% PCE obtained by porphyrins, [7] their closest relatives. Light harvesting ability of QDs and Pcs can be enhanced by binding them, either covalent or supramolecular, producing a system capable to charge injection from both chromophores.However, the chemical combination of Pc rings to QDs has hardly been explored probably due to the difficulties to synthesize Pcs with the adequate anchoring groups. Until now just a few articles have been published where Pcs are covalently linked to QDs showing in most of the cases Förster resonance energy transfer (FRET) from QDs to Pcs. SiPc has been connected to CdSe QDs through axial ligation, [8] and also tetraminoZnPc [9] and unsymmetrically tris-tert-butyl-imidoZnPc [10] have been li...

Two phthalocyanines possessing carboxylate groups ((TBA)4H2Pc·1 and (TBA)4H2Pc·2) form 1:2 supramolecular complexes with lithium cation-encapsulated C60 (Li(+)@C60) [H2Pc·1(4-)/(Li(+)@C60)2 and H2Pc·2(4-)/(Li(+)@C60)2] in a polar mixed solvent. From the UV-vis spectral changes, the binding constants (K) were estimated as ca. 10(12) M(-2). Upon the photoexcitation of constructed supramolecular complexes, photoinduced electron transfer occurred to form the charge-separated (CS) state. The lifetime of the CS state was determined to be 1.2 ms for H2Pc·2(4-)/(Li(+)@C60)2, which is the longest CS lifetime among the porphyrinoid/fullerene supramolecular complexes. H2Pc·1(4-)/(Li(+)@C60)2 also afforded the long-lived CS state of 1.0 ms. The spin state of the long-lived CS states was determined to be a triplet, as indicated by the EPR signal at g = 4. The reorganization energy (λ) and the electronic coupling term were determined to be λ = 1.70 eV, V = 0.15 cm(-1) from the temperature dependence of the rate constant for the charge recombination of the CS state of H2Pc·1(4-)/(Li(+)@C60)2. The energy of the CS state (0.49 eV) is much smaller than the reorganization energy, indicating that the back-electron-transfer process is located in the Marcus normal region. The small electronic coupling term results from the spin-forbidden back electron transfer due to the triplet CS state. Supramolecular complexes of anionic zinc phthalocyanines with Li(+)@C60 were also prepared and investigated. The ZnPc·4(4-)/Li(+)@C60 supramolecular nanoclusters were assembled on the optically transparent electrode (OTE) of nanostructured SnO2 (OTE/SnO2) to construct the dye-sensitized solar cell. The IPCE (incident photon-to-photocurrent efficiency) values of OTE/SnO2/(ZnPc·4(4-)/Li(+)@C60)n were much higher than the sum of the two IPCE values of the individual systems OTE/SnO2/(Li(+)@C60)n and OTE/SnO2/(ZnPc·4(4-))n, covering the near-infrared region.

The power conversion efficiency of CdSe and CdS quantum dot sensitized solar cells is enhanced up to 45% for CdSe and 104% for CdS by passivation with an asymmetrically disulfide substituted phthalocyanine.

Here, we have developed an organic photocathode for water reduction to H , delivering more than 1 mA cm at 0 V versus RHE and above 3 mA cm at -0.5 V versus RHE with moderate stability under neutral pH conditions. The initial competitive reduction of water to H and ZnO to metallic Zn is responsible for the dynamic behaviour of both photocurrent and Faradaic efficiency of the device, which reaches 100 % Faradaic efficiency after 90 min operation. In any case, outstanding stable H flow of approximately 2 μmol h is measured over 1 h at 0 V versus RHE and at neutral pH, after equilibrium between the Zn /Zn concentration in the AZO film is reached. This achievement opens new avenues for the development of allsolution-processed organic photoelectrochemical cells for the solar generation of H from sea water.