A series of triphenylamine dyes were designed and synthesized as photosensitizers for the application of organic dye-sensitized solar cells (DSSCs). Different substituted phenylene units, 2,2′;5′,2′′-terthiophene (TT) and dithieno[3,2-b;2′,3′-d]thiophene (DTT) serve as the π-spacers, and the electron acceptors employ the cyanoacrylic acid or rhodanine-3-acetic acid units. Detailed investigation on the relationship between the dye structure, and photophysical, photoelectrochemical properties and performance of DSSCs is described here. By substituting the phenylene group with electron-withdrawing units as π-spacers or replacing the cyanoacrylic acid with rhodanine-3-acetic acid units as electron acceptors, the bathochromic shift of absorption spectra are achieved. The significant differences in the redox potential of these dyes are also influenced by small structure changes. Furthermore, the different dye baths for semiconductor sensitization have a crucial effect on the performance of the DSSCs due to the different absorbed amount, absorption spectra and binding modes of anchored dyes on TiO 2 surface in various solvents. On the basis of optimized dye bath and molecular structure, TPC1 shows a prominent solar-to-electricity conversion efficiency (η), 5.33% (J SC ) 9.7 mA · cm -2 , V OC ) 760 mV, ff ) 0.72), under simulated AM 1.5G irradiation (100 mW · cm -2 ). Density functional theory has employed to study the electron distribution and the intramolecular charge transfer (HOMOfLUMO) of the dyes. From the calculation results of the selected dyes, we can also find the cyanoacrylic acid unit is better than the rhodanine-3-acetic acid unit as electron acceptor. Also, the electron-withdrawing groups on phenylene units as π-spacers show the negative effect on the performance of the organic DSSCs.

Two carbazole-based small molecule hole-transport materials (HTMs) are synthesized and investigated in solid-state dye-sensitized solar cells (ssDSCs) and perovskite solar cells (PSCs). The HTM X51-based devices exhibit high power conversion efficiencies (PCEs) of 6.0% and 9.8% in ssDSCs and PSCs, respectively. These results are superior or comparable to those of 5.5% and 10.2%, respectively, obtained for the analogous cells using the state-of-the-art HTM Spiro-OMeTAD.

An organic polymer nano-photocatalyst has been developed for highly efficient light driven proton reduction.

Novel organic dyes based on the phenothiazine (PTZ) chromophore were designed and synthesized for dye-sensitized solar cells, which give solar energy-to-electricity conversion efficiency (eta) of up to 5.5% in comparison with the reference Ru-complex (N3 dye) with an eta value of 6.2% under similar experimental conditions.

For the first time, organic semiconducting polymer dots (Pdots) based on poly[(9,9'-dioctylfluorenyl-2,7-diyl)-co-(1,4-benzo-{2,1',3} thiadiazole)] (PFBT) and polystyrene grafting with carboxyl-group-functionalized ethylene oxide (PS-PEG-COOH) are introduced as a photocatalyst towards visible-light-driven hydrogen generation in a completely organic solvent-free system. With these organic Pdots as the photocatalyst, an impressive initial rate constant of 8.3 mmol h(-1)  g(-1) was obtained for visible-light-driven hydrogen production, which is 5-orders of magnitude higher than that of pristine PFBT polymer under the same catalytic conditions. Detailed kinetics studies suggest that the productive electron transfer quench of the excited state of Pdots by an electron donor is about 40 %. More importantly, we also found that the Pdots can tolerate oxygen during catalysis, which is crucial for further application of this material for light-driven water splitting.

S2(A) Synthesis and photophysical data for the intermediates and sensitizers: General: 1 H NMR Spectra were recorded with a Varian INOVA 400NMR instrument.MS data were obtained with GCT CA156 (UK) high resolution mass spectrometer (HRMS) or HP1100 LC/MSD (USA) mass spectrometer. UV-vis spectra of the dyes in solutions were recorded in a quartz cell with 1 cm path length on a HP 8453 spectraphotometer. Melting-points were measured with a X-4 melting-point apparatus with microscope.The several of π-conjugating spacers 5a-8a were prepared using known procedures. 5a and 6a were prepared by Suzuki coupling of 2-thienylboronic acid with corresponding 2-bromothiophene and 2,5-dibromothiophene, respectively. 7a was obtained in 3 steps from 3-bromothiophene according to the already reported procedures. [1,2] 8a of E-configuration was prepared by McMurry coupling of 2-thiophenecarboxaldehyde. [3] 2,2,4-Trimethyl-1,2-dihydro-quinoline(1a)To a solution of aniline (18.7 g, 0.2 mol) and toluenesulfonic acid (1.9 g) in cyclohexane (20 mL), acetone (42 mL, 0.57 mol) was added dropwise at 80~90 ºC for 8~10 h. The resulted water was removed by co-boiling with cyclohexane. Sodium carbonate (0.55 g) in water (20 mL) was poured into the reaction mixture after complete addition of acetone at 70 ºC. The reaction mixture was stirred overnight at r.t. The organic layer was washed with water and dried over magnesium sulfate. The unreacted acetone and solvent was romoved by rotary evaporation. The residue was distilled in vacuo to give 1a as colorless oil (130 ºC/10 mmHg, 17 g, 49%). 1 H NMR

A series of organic thiolate/disulfide redox couples have been synthesized and have been studied systematically in dye-sensitized solar cells (DSCs) on the basis of an organic dye (TH305). Photophysical, photoelectrochemical, and photovoltaic measurements were performed in order to get insights into the effects of different redox couples on the performance of DSCs. The polymeric, organic poly(3,4-ethylenedioxythiophene) (PEDOT) material has also been introduced as counter electrode in this kind of noniodine-containing DSCs showing a promising conversion efficiency of 6.0% under AM 1.5G, 100 mW·cm(-2) light illumination. Detailed studies using electrochemical impedance spectroscopy and linear-sweep voltammetry reveal that the reduction of disulfide species is more efficient on the PEDOT counter electrode surface than on the commonly used platinized conducting glass electrode. Both pure and solvated ionic-liquid electrolytes based on a thiolate anion have been studied in the DSCs. The pure and solvated ionic-liquid-based electrolytes containing an organic redox couple render efficiencies of 3.4% and 1.2% under 10 mW·cm(-2) light illumination, respectively.

A modified polysulfide redox couple, [(CH(3))(4)N](2)S/[(CH(3))(4)N](2)S(n), in an organic solvent (3-methoxypropionitrile) was employed in CdS quantum dot (QD)-sensitized solar cells (QDSSCs), and an unprecedented energy conversion efficiency of up to 3.2% was obtained under AM 1.5 G illumination. The QDs were linked to nanoporous TiO(2) via covalent bonds by using thioglycolic acid, and chemical bath deposition in an organic solvent was then used to prepare the QDSSCs, facilitating high wettability and superior penetration capability of the TiO(2) films. A very high fill factor of 0.89 was observed with the optimized QDSSCs.