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Anchoring porphyrin, ZnPAc, featuring cyanoacetic acid group has been synthesized for application in a dye-sensitized solar cell. Capping layer dyes zinc meso-tetraphenyl porphyrin (ZnTPP) with anchoring porphyrin ZnPAc through axial coordination bonds of Zn-to-ligand self-assembles solar cell devices. With the introduction of cyanoacetic acid anchor, the higher electrons are effectively injected into the TiO2 semiconductor surface. Thus, the ZnTPP-ZnPAc-based device has more short-circuit current (JSC) compared with our previously reported ZnTPP-ZnPA-based solar cell. The ZnPA and ZnPAc porphyrin anchoring dyes maintain a broad absorption spectrum and also improve electron injection and lower charge recombination compared to our previous reports on organic molecule anchored dye W3. Hence, the ZnTPP-ZnPAc self-assembled dye has higher power conversion efficiency. The assembled modes were also verified by transmission electron microscopy (TEM). To understand ZnTPP-ZnPAc for photovoltaic performance trends, we have carried out charge extraction, transient photovoltage decay and electrochemical impedance spectroscopy analysis. [ABSTRACT FROM AUTHOR]

A new self-assemblies based on double-deck dyes ZnTPP-Wi (i = 1–3) were synthesized and applied in dye-sensitized solar cells (DSSCs). Anchoring molecules (Wi i = 1–3) consisting of phenyl carboxyl acid and cyanoacetic acid group. Capping layer dyes zinc meso-tetraphenylporphine (ZnTPP) with anchoring molecules Wi through axially coordination bonds of Zn-to-ligand self-assemblies solar cells devices. We herein report a consisting acylamide and cyanoacetic acid group W3 as an anchoring molecule for the axial coordination with upper zinc porphyrin ZnTPP. W3 was synthesized by introducing acylamide and cyanoacetic acid groups may inhibit adverse dye aggregation and improving electrons are effectively injected into the TiO2 semiconductor surface. Thus, W3 anchoring molecules can be used to fabricate efficient solar cells with ZnTPP porohyrin dye, achieving good photoelectric performance, indicative of their general applicability in fabricating good-performance DSSCs. The assembled modes were also verified by transmission electron microscopy (TEM). The photoelectrochemical efficiencies for dye ZnTPP-W3 are best than those of self-assembly dyes prevailingly ascribed to larger Jsc and Voc. [ABSTRACT FROM AUTHOR]

We have synthesized tetrazolium anchor porphyrin (MPTz) with different metal ions (M, M = Zn2+, Cd2+ and Co2+) and triphenylamine group antenna molecule L2 on the nanostructured TiO2 electrode surfaces, resulting in a ZnPTz + L2 assembled approach, based on self-assembled dye ZnPTz + L2 for highly efficient dye-sensitized solar cells (DSSCs). The photoelectric conversion efficiency of solar cells sensitized by the dyes with antenna molecule (L2) were enhanced when compared to that sensitized by the dye with monolayer anchor porphyrin (ZnPTz). We have carefully examined their optical and electrochemical properties and device performance. In addition, the modes of the assemblies immobilized on TiO2 electrode surfaces were also verified by transmission electron microscopy (TEM). [ABSTRACT FROM AUTHOR]

Two new self-assemblies based on zinc porphyrin dyes ZnPx-ZnPA (x = 1, 2) were synthesized and used for dye-sensitized solar cells. Capping layer dyes consist of zinc porphyrin (ZnP) as core unit and carbazole (P1), phenothiazine (P2) as electron-donating group. The dye ZnPA contains carboxylic group as an anchor porphyrin with upper dyes (denoted as ZnP1 and ZnP2) formed dyads by coordination bonds of Zn-to-ligand self-assembled devices. The assembly modes were also verified by transmission electron microscopy (TEM). The influence of the upper porphyrins on molecular structure as well as photovoltaic performance was investigated via photophysical and electrochemical studies and calculations. With addition of the phenothiazine unit, the ZnP2-ZnPA possesses better light-harvesting capability with a significantly red-shifted Q-band. The photoelectrochemical efficiencies for ZnP2-ZnPA are better than those of ZnP1-ZnPA ascribed to larger Jsc and Voc. [ABSTRACT FROM AUTHOR]

We have designed a self-assemblyZnP-ZnPA, based on a porphyrinZnPbearing 1,3,5-triazine-2,4-diamine unit, and anchoring porphyrinZnPA. The assembly withZnP-ZnPAwas immobilized on nanostructured TiO2electrode surfaces. The assembled structures were characterized by transmission electron microscopy. The optical, photovoltaic, electrochemical impedance spectroscopy, and incident photon-to-current conversion efficiency were measured. The results revealed that theZnP-ZnPAdevice had better photovoltaic performance thanZnPAand possessed a higher shortcircuit photocurrent density (JSC = 6.04) but a lower open-circuit photovoltage (VOC = 0.51) than anchoringZnPA. Moreover, our previously reported assembly (ZnP-A1) as reference, the assembly deviceZnP-ZnPAhad betterη(2.24%) and FF (72.7%). [ABSTRACT FROM PUBLISHER]

An acylhydrazone zinc porphyrin P1 and its coordination polymers (CPs, denoted as P1M, M = Mn, Co, Ni, Cu, Zn) with different metal ions (Mn2+, Co2+, Ni2+, Cu2+ and Zn2+) were synthesized. Then these coordination polymers were assembled into bilayer structured supramolecular chromophores through axially coordinating with anchoring porphyrin AP, and their performance in dye sensitized solar cells was investigated. Our results reveal that the bilayer structured supramolecular chromophore based solar cells show significantly improved photocurrent conversion efficiency. Particularly, P1Mn and P1Zn based solar cells showed a relatively higher short circuit current density (JSC) due to their broad absorption bands and remarkable light harvesting abilities. Meanwhile, the VOC values of the cells fabricated with the bilayered chromophores slightly decreased. Electrochemical impedance spectroscopy (EIS) in combination with charge extraction (CE) and transient photovoltage decay (TPD) measurements indicates that the decreased VOC resulted from the vigorous electron recombination and the downward shifted conduction band edge (ECB) of titania. [ABSTRACT FROM AUTHOR]

In this work, two new self-assemblies based on zinc porphyrins substituted at the meso-positions with different donor units (denoted asZnP1andZnP2) and anchor porphyrin(ZnPA)dyads formed by the coordination bonds of Zn-to-ligand have been prepared. Further, the assemblies were absorbed on semiconducting TiO2electrode surfaces by the carboxylic groups of anchor porphyrin(ZnPA), and their photovoltaic performances in solar cells were performed under 100 mW cm−2AM 1.5G sunlight. Photoelectrochemical studies reveal a significantly improved photovoltaic behavior for the dyad of triphenylamine-based zinc porphyrin(ZnP1)compared to the dyad with trimethylamine-based zinc porphyrin. The results were verified by electrochemical impedance spectroscopy, calculations, and optical performance. In addition, the modes of the assemblies immobilized on TiO2electrode surfaces were also verified by transmission electron microscopy. [ABSTRACT FROM PUBLISHER]

We prepared in this work an anchoring porphyrin and a series of hat-porphyrins. The zinc atom of the hat-porphyrins can be coordinated axially with the pyridine moiety of the anchoring porphyrin which is anchored on the titania surface by a carboxyl group. The structures of the assemblies were confirmed using computational calculations, transmission electron microscopy (TEM) and energy dispersive spectrometry (EDS). Solar cell devices of the monomer anchoring porphyrin and its assemblies were fabricated and the photovoltaic performances were measured under standard AM 1.5 sunlight irradiance. We found that the assembly devices showed higher JSC and lower VOC than that of the monomer anchoring porphyrin device. However, the comprehensive influence of JSC and VOC led to an enhancement in the solar-to-electric power-conversion efficiency (PCE) of the assemblies. We also studied the variation of JSC and VOC using electronic absorption and emission spectroscopy, charge extraction measurements, transient photovoltage decay measurements and electrochemical impedance spectroscopy. [ABSTRACT FROM AUTHOR]

In this work, two Schiff base porphyrins have been successfully synthesized. The metal-ligand axial coordination assembling strategy has been used to organize two assemblies based on the two porphyrins appended isonicotinic acid ligands. Further, the assemblies were absorbed on the semiconducting TiO electrode surfaces by the carboxylic groups of isonicotinic acid ligands, and their photovoltaic performances were performed under irradiance of 100 mW cm AM 1.5G sunlight. Photoelectrochemical studies show a significantly enhanced photovoltaic behavior for phenol-based zinc porphyrin assembly compared to pyridine-based zinc porphyrin assembly. The UV-Vis absorption, fluorescence spectra, molecular orbital patterns, and HOMO-LUMO energy gaps of the assemblies were also performed to further understand their photovoltaic features. In addition, the assembled modes of the assemblies immobilized on TiO electrode surfaces were also verified by transmission electron microscopy. [ABSTRACT FROM AUTHOR]

In this work, a new zincmeso-tetra[3-(1H-imidazol-1-yl)phenyl]porphyrin (ZnP) was synthesized. Further, the porphyrinZnPwas immobilized by metal-ligand axial coordination (ZnP-A) and a metal-ligand edged binding approach (ZnP-Zn-A) on the nanostructured TiO2electrode surface modified with coordinating ligand functionality, isonicotinic acid (A). The performances of the assemblies-sensitized solar cells were performed under irradiance of 100 mW?cm?2AM 1.5G sunlight. Photo-electrochemical studies reveal significantly improved performance of the assemblyZnP-A. These assemblies can afford a fertile base for further design and fabrication of new supramolecular solar cells in future. [ABSTRACT FROM PUBLISHER]

InGaN/GaN multiple quantum well (MQW) solar cells with stepped-thickness quantum wells (SQW) are designed and grown by metal-organic chemical vapor deposition. The stepped-thickness quantum wells structure, in which the well thickness becomes smaller and smaller along the growth direction, reveals better crystalline quality and better spectral overlap with the solar spectrum. Consequently, the short-circuit current density (Jsc) and conversion efficiency of the solar cell are enhanced by 27.12% and 56.41% compared with the conventional structure under illumination of AM1.5G (100 mW/cm²). In addition, approaches to further promote the performance of InGaN/GaN multiple quantum well solar cells are discussed and presented. [ABSTRACT FROM AUTHOR]

Four metal atom dyes as upper porphyrins and horizontal anchor porphyrin to construct axial-coordinated assemblies. Then these assemblies were immobilized on TiO 2 electrode surface for impressive improvement of photocurrent response in supramolecular solar cell. [Display omitted] Four different metal atom dyes MP (M: Zn, Cd, Ag, Cu) as upper porphyrin molecular have been designed and synthesized. On the other side of ZnPA contains four carboxylic acids as the horizontal anchor porphyrin for binding to TiO 2. We constructed MP-ZnPA assembled approach, and applied in dye-sensitized solar cells. Photoelectrochemical studies reveal the self-assembled structure dye photocurrent (J sc) are higher than anchor porphyrin. The enhancement of J sc can be ascribed to the improved light-harvesting ability induced by the axially coordinated MP. However, upper different metal atom porphyrins cannot play a positive role in improving the photovoltages (V oc) because of MP-ZnPA devices possess the dye aggregation. The effects of the MP-ZnPA assembled on the optical, theory calculations and photovoltaic properties were investigated. AgP-ZnPA and ZnP-ZnPA have the higher molar extinction coefficient and sufficient charge injection into the TiO 2 conduction band. Therefore, AgP-ZnPA and ZnP-ZnPA have superior photovoltaic behavior. We constructed a three-layer self-assembled (ZnP1-AgP-ZnPA) solar cell, which the photovoltaic efficiency of the three-layer self-assembled solar cell is significantly reduced. Consequently, double-layer self-assembly, which is one of the effective strategies for improving the performance of self-assembly supramolecular solar cells. [ABSTRACT FROM AUTHOR]

Two new acetohydrazide zinc porphyrin with different donor units based Mn (Ⅱ) ion coordination polymers ( CPsx , x = 1,2 ) have been designed, synthesized, and well-characterized. Two coordination polymers and anchor porphyrin ( ZnPA ) self-assembly by metal-ligand axial coordination to modify the nano-structured TiO 2 electrode surface has been investigated in photoelectrochemical device. Our results reveal that the self-assemblies devices show significantly improved photocurrent conversion efficiency. Particularly, CPs1 based solar cell showed higher short circuit current density and conversion efficiency. Their optical performance, electrochemical impedance spectroscopy and transient photovoltage decay were also investigated to further understand the photoelectrochemical results. In addition, the assembled modes of the assemblies immobilized on TiO 2 electrode surfaces were also verified by transmission electron microscopy (TEM), theory calculations and energy dispersive X-ray spectroscopy (EDX). [ABSTRACT FROM AUTHOR]

Porphyrins are promising DSSC sensitizers focused on novel anchoring. Herein, three horizontal anchor zinc porphyrins have been designed, synthesized, and well-characterized. Their optical, photovoltaic, theory calculation and electrochemical performances in dye-sensitized solar cells were investigated. Absorption spectra indicated the stronger H-aggregation in ortho carboxylic acid anchor porphyrin ( o - ZnPA ) than that in meta carboxylic acid anchor porphyrin ( m - ZnPA ) on the surface of TiO 2 nanoparticles. The photoelectric conversion efficiency studies showed a significantly enhanced photovoltaic behavior for meta carboxylic acid anchor porphyrin ( m - ZnPA ) compared to meta tetrazolium anchor porphyrin ( m - ZnPTz ). The infrared spectroscopies, theory calculations and the electrochemical impedance spectroscopies revealed that carboxylic acid anchoring binding modes could increase the efficiency of electron injection. [ABSTRACT FROM AUTHOR]

Highlights: [•] Metal (Mn and Cd)-mediated assemblies of two acetohydrazide zinc porphyrins. [•] Porphyrins appended organic acid entities were immobilized on TiO2 films. [•] Enhanced photovoltaic behavior of Mn-mediated assembly of phenol–porphyrin. [•] This work affords a fertile base for supramolecular solar cells. [Copyright &y& Elsevier]

Highlights: [•] The metal-mediated assembling strategy for organizing zinc porphyrin. [•] A series of differently bivalent metal ions were prepared. [•] A series of differently anchoring groups were also prepared. [•] Significant improvement in solar-to-electrical conversation efficiency. [•] Well-arrays of zinc porphyrins on the TiO2 electrode surfaces were reflected. [ABSTRACT FROM AUTHOR]

Highlights: [•] Porphyrins appended isonicotinic acid ligands were immobilized on TiO2 films. [•] The dyad of tetrazole-based porphyrin shows enhanced photovoltaic behavior. [•] This work affords a fertile base for supramolecular solar cells. [ABSTRACT FROM AUTHOR]

Highlights: [•] A novel assembly with acetohydrazide porphyrin coordination polymer. [•] The assembly based on porphyrin is prepared as parallel sample. [•] Coordination polymer-based assembly shows enhanced photoelectronic behavior. [•] A series of different organic acid ligands as anchoring groups are prepared. [ABSTRACT FROM AUTHOR]

Highlights: [•] A novel self-assembly with porphyrin coordination polymer on TiO2 film. [•] Three zinc porphyrin and their respective Hg(II) coordination polymers. [•] The X-ray structure of a Hg(II) porphyrin coordiantion polymer. [•] Significantly enhanced the current-voltage behavior of these assemblies. [Copyright &y& Elsevier]

Abstract: Two new self-assemblies based on two zinc porphyrins substituted at the meso-positions with different donor units (denoted as ZnP1 and ZnP2) and isonicotinic acid (A) by metal–ligand axial coordination have been designed and immobilized on the double-layer nanostructured TiO2 film-coated highly transparent FTO conducting glass electrode in a photosynthesis device. These cells were also measured under irradiance of 100mWcm−2 AM 1.5G sunlight. The results reveal that the performance of ZnP2-A outperforms that of ZnP1-A. The UV–vis absorption spectra, fluorescence spectra, molecular orbital (MO) patterns, and HOMO–LUMO energy gaps of these assemblies were also investigated to further demonstrate the photovoltaic behavior of these cells. [Copyright &y& Elsevier]