@article { ISI:000299212700017, title = {Tuning spectral properties of phenothiazine based donor-pi-acceptor dyes for efficient dye-sensitized solar cells}, journal = {Journal of Materials Chemistry}, volume = {22}, number = {3}, year = {2012}, month = {NOV}, pages = {889-894}, publisher = {ROYAL SOC CHEMISTRY}, type = {Article}, address = {THOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON RD, CAMBRIDGE CB4 0WF, CAMBS, ENGLAND}, abstract = {

Two novel metal-free organic donor-pi-acceptor dyes were synthesized using electron-rich 10-butyl-(2-methylthio)-10H-phenothiazine as a donor and cyanoacrylic acid as an acceptor. The spectral response of the dye was tuned by introducing a vinylene thiophene pi-bridge. Obtained optical and electrochemical properties of the dyes seemed to be promising in terms of employing them as light harvesters in dye-sensitized solar cells (DSCs). The efficiencies of the devices under standard AM 1.5G (100 mW cm(-2)) conditions reached 7.3\% with volatile electrolyte. The differences in the photovoltaic parameters of these DSCs were explained by comparing the results of electrochemical impedance spectroscopy (EIS) measurements and transient photovoltage and photocurrent decay experiments.

}, issn = {0959-9428}, doi = {10.1039/c1jm14024h}, author = {Marszalek, Magdalena and Nagane, Satyawan and Ichake, Amol and Humphry-Baker, Robin and Paul, Vincent and Zakeeruddin, Shaik M. and Graetzel, Michael} } @article { ISI:000318634000040, title = {Structural variations of D-pi-A dyes influence on the photovoltaic performance of dye-sensitized solar cells}, journal = {RSC Advances}, volume = {3}, number = {21}, year = {2013}, month = {MAR}, pages = {7921-7927}, publisher = {ROYAL SOC CHEMISTRY}, address = {THOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON RD, CAMBRIDGE CB4 0WF, CAMBS, ENGLAND}, abstract = {

Two new organic D-pi-A dyes containing identical pi-conjugated spacer and anchoring/acceptor moieties but different donor groups were designed and synthesized. These dyes containing didodecylcyclopentadithiophene (CPDT) as a spacer, cyanoacrylic acid as an acceptor and N-butyl-carbazole or N-butyl-phenothiazine moieties as electron donor groups are labelled as V4 and V11 dyes, respectively. The variation in the donor group of these two dyes, that influences the photophysical, electrochemical and photovoltaic parameters, was investigated. The highest photovoltaic conversion efficiency of 7.5\% was obtained with V4 dye at AM 1.5 G full sunlight intensity (100 mWcm(-2)). Comparison of phenothiazine donor dyes with two different pi-conjugated spacers, CPDT (V11) and vinyl thiophene (V7) containing devices shows that the V-oc of V7 dye is lower than that of V11 due to the downward shift of the conduction band edge. Transient photovoltage and electrochemical impedance spectroscopy measurements were performed to explain the differences in the PV parameters by varying the donors and/or spacer groups.

}, issn = {2046-2069}, doi = {10.1039/c3ra22249g}, author = {Marszalek, Magdalena and Nagane, Satyawan and Ichake, Amol and Humphry-Baker, Robin and Paul, Vincent and Zakeeruddin, Shaik M. and Gratzel, Michael} } @article {42969, title = {Phenothiazine-based D-A-π-A dyes for highly efficient dye sensitized solar cells: effect of internal acceptor and non-conjugated π-spacer on device performance}, journal = {ChemPlusChem}, volume = {82}, year = {2017}, month = {FEB}, pages = {280-286}, abstract = {Three new D-A-pi-A metal-free organic dyes based on phenothiazine as a donor (D) and non-conjugated pi-spacer were designed and synthesized. The incorporation of different {\textquoteright}internal acceptors{\textquoteright} (electron traps) such as benzothiadiazole (BTD), benzotriazole (BTA), and pyridine were shown to allow systematic tuning of the energy levels and the photophysical properties. The AI-1 dye showed lower electronic disorder compared with the other two dyes. The efficiencies achieved with AI-1, AI-2, and AI-3 dyes were 8.5\% (J(sc) = 15.42 mA cm(-2), V-oc = 0.78 V, FF = 68\%), 7\% (J(sc) = 12.8 mA cm(-2), V-oc = 0.78 V, FF = 68\%) and 6.7\% (J(sc) = 11.57 mA cm(-2), V-oc = 0.82 V, FF = 68.26 \%), respectively. The incorporation of non-conjugated phenothiazine as a p-spacer in D-A-pi-A dyes showed remarkable enhancement in the photovoltaic performance of dye-sensitized solar cell (DSSC) devices. The sealed DSSC devices with iodide/tri-iodide (I-/I-3(-) @)based liquid electrolyte showed promising stability under ambient conditions.}, doi = {10.1002/cplu.201600492}, author = {Nagane, Satyawan and Ichake, Amol and Agrawal, Ishita and Sadhanala, Aditya and Friend, Richard H. and Ogale, Satishchandra and Wadgaonkar, Prakash P.} } @article {44548, title = {Phenazine-containing poly(phenylenevinylene): a new polymer with impressive field emission properties}, journal = {Journal of Polymer Research}, volume = {25}, year = {2018}, month = {FEB}, pages = {Article Number: 61}, abstract = {

Phenazine-containing poly(phenylenevinylene) (P(PHN-PV)) was synthesized using Wittig-Horner polycondensation of the appropriately designed monomers viz. 5,10-dioctyl-5,10-dihydrophenazine-2,7-dicarbaldehyde and tetraethyl ((2,5-bis((2-ethylhexyl) oxy)-1,4 phenylene) bis(methylene)) bis(phosphonate). The design embraces the specific motivation of incorporating the nitrogen-containing heterocycle viz. .phenazine in poly(phenylenevinylene) backbone. P(PHN-PV) exhibited reversible redox properties. In the field emission measurements performed on the film of P(F{\textquoteright}HN-PV), the turn-on field was observed to be 1.93 V/mu m for the current density of 10 mu A/cm(2). The maximum current density of similar to 4.87 mA/cm(2) was achieved at the applied field of 3.84 V/mu m. The emission current showed impressive stability for 6 h at a constant current of 1 mu A (current density of about 20 mu A/cm(2)). These results emphasize the role of phenazine heterocycle with lone pair of electrons on nitrogen in lowering the oxidation onset and in turn reduction of the turn-on voltage.

}, keywords = {field emission, Phenazine, Poly(phenylenevinylene)}, issn = {1022-9760}, doi = {10.1007/s10965-017-1428-8}, author = {Chhatre, Shraddha and Ichake, Amol and Harpale, Kashmira and Patil, Sumati and Deshpande, Aparna and More, Mahendra and Wadgaonkar, Prakash P.} }