Jian-Yu Zheng

New Donor-π-Acceptor Type Triazatruxene Derivatives for Highly Efficient Dye-Sensitized Solar Cells

A new class of organic dyes based on triazatruxene have been designed and synthesized for dye-sensitized solar cells. The photoelectronic properties of these donor-π-acceptor dyes can be tuned by changing π-conjugated linkers. The best performance was found for triazatruxene dye TD1, wherein, with thiophene as the conjugated linker and cyanoacrylic acid as the acceptor, a power conversion efficiency up to 6.10% was achieved.

Benzo[a]carbazole-Based Donor−π–Acceptor Type Organic Dyes for Highly Efficient Dye-Sensitized Solar Cells

A novel class of metal-free organic dyes based on benzo[a]carbazole have been designed, synthesized, and used in dye-sensitized solar cells for the first time. These types of dyes consisted of a cyanoacrylic acid moiety as the electron acceptor/anchoring group and different electron-rich spacers such as thiophene (JY21), furan (JY22), and oligothiophene (JY23) as the π-linkers. The photophysical, electrochemical, and photovoltaic properties, as well as theoretical calculations of these dyes were investigated. The photovoltaic performances of these dyes were found to be highly relevant to the π-conjugated linkers. In particular, dye JY23 exhibited a broad IPCE response with a photocurrent signal up to about 740 nm covering the most region of the UV-visible light. A DSSC based on JY23 showed the best photovoltaic performance with a Jsc of 14.8 mA cm(-2), a Voc of 744 mV, and a FF of 0.68, achieving a power conversion efficiency of 7.54% under standard AM 1.5 G irradiation.

An efficient PIFA-mediated synthesis of fused diporphyrin and triply-singly interlacedly linked porphyrin array.

An efficient and metal-free oxidative method was reported for synthesis of triply linked diporphyrins with 2.5 equiv of phenyliodine bis(trifluoroacetate) (PIFA). This reaction showed high selectivity for Zn(II) porphyrins and had been successfully applied in the synthesis of a novel triply-singly interlacedly linked porphyrin array with lower energy gap.

Simple and catalyst-free synthesis of meso-O-, -S-, and -C-substituted porphyrins.

A simple and efficient method for the meso-functionalization of porphyrin has been developed. Kinetic studies of meso-fluoro-, -chloro-, -bromo-, -iodo-, and -nitro-substituted porphyrins (Ni) with phenol reveal that the reaction undergoes a typical aromatic nucleophilic substitution (SNAr) process. This catalyst-free method can be performed with meso-brominated porphyrins and oxygen-, sulfur-, and carbon-based nucleophiles to achieve a wide variety of meso-substituted porphyrins.

Metal-Free Iodine(III)-Promoted Synthesis of Isoquinolones

A metal-free oxidative cycloaddition reaction of substituted benzamides and alkynes has been developed for the synthesis of isoquinolones by using bis(trifluoracetoxy)iodobenzene (PIFA) and trifluoroacetic acid (TFA). Under mild conditions, a wide variety of isoquinolones were conveniently prepared via oxidative annulation of simple N-methoxybenzamide and diarylacetylene or aryl/alkyl acetylene derivatives in yields up to 87%.

Biindole-based double D–π–A branched organic dyes for efficient dye-sensitized solar cells

A novel class of double D–π–A branched organic dyes based on 2,2′-disubstituted-1H,1′H-3,3′-biindole moiety have been synthesized, characterized and applied as photosensitizers for dye-sensitized solar cells. Their photophysical, electrochemical and photovoltaic properties are further investigated. These type of organic dyes contain two cyanoacrylic acid moieties as electron acceptors/anchoring groups and different electron-rich conjugated linkers such as furan (JY11), thiophene (JY12) and 2,2′-bithiophene (JY13) as π-bridges. The superiority of the cross X-shaped structure of these double D–π–A branched organic dyes is the suppression of the intermolecular interactions and the guarantee of fast electron injection into the TiO2 semiconductor in the dye-sensitized solar cells. A highest power conversion efficiency of 6.54% was achieved for JY13-based cell with an iodine electrolyte under simulated AM 1.5 G solar irradiation (100 mW cm−2).

Diastereoselective synthesis of chiral diporphyrins via intramolecular meso-meso oxidative coupling.

Diastereoselective syntheses of meso-meso linked diporphyrins were achieved via intramolecular chiral induction. The structures and conformations were analyzed by CD, UV, NMR, and computational calculations.

An efficient PIFA-mediated synthesis of a directly linked zinc chlorin dimer via regioselective oxidative coupling.

The synthesis of a directly linked zinc chlorin dimer was first achieved by a facile and efficient oxidative coupling of zinc chlorin monomers with phenyliodine bis(trifluoroacetate) (PIFA). The reaction shows high regioselectivity at the 20-position near the hydrogenated pyrrole ring producing selective dichlorin in 74% yield.

Noncovalent Functionalization of Single-Walled Carbon Nanotube by Porphyrin: Dispersion of Carbon Nanotubes in Water and Formation of Self-Assembly Donor-Acceptor Nanoensemble

A water-soluble nanoensemble of porphyrin and single-walled carbon nanotubes (SWNTs) was fabricated via electrostatic attraction. The formation of this supramolecular complex was monitored by UV-vis spectra and fluorescence spectra. The donor-acceptor properties of this nanoensemble were characterized by I–V performance of relative photovoltaic device fabricated by layer-by-layer (LBL) technique.

Phenothiazine-functionalized push–pull Zn porphyrin photosensitizers for efficient dye-sensitized solar cells

A series of zinc porphyrin dyes (JY24–27) featured phenothiazine moieties have been synthesized and applied as photosensitizers in dye-sensitized solar cells. The phenothiazine donors were directly attached to the meso-position of porphyrins, and different π-linkers (benzene, thiophene and ethynyl benzene) and acceptor groups (carboxylic acid and cyanoacrylic acid) were applied to tune the photoelectric properties of these push–pull porphyrin dyes. The photophysical, electrochemical and theoretical studies revealed that the synthesized porphyrin dyes were all capable of being used as photosensitizer. The dye JY27 with an extended conjugation by introducing ethynyl group exhibited a broader absorption region and more significantly improved IPCE values between 550 and 750 nm than the other three dyes, which ensured a good light-harvesting ability and a high short-circuit current density of 15.3 mA cm−2. Finally, JY27-based cell achieved a high efficiency of 6.25% under standard simulated irradiation.