02578nas a2200181   4500008004100000245017900041210006900220260000800289300001600297490000600313520181900319100002502138700002902163700002802192700002402220700002702244856012502271       2016                        eng d00aEffect of out-of-plane alkyl group's position in dye-sensitized solar cell efficiency: a structure-property relationship utilizing indoline-based unsymmetrical squaraine dyes0 aEffect of outofplane alkyl groups position in dyesensitized sola  cDEC  a35353-353670 v83 a<p>Squaraine dyes are promising chromophores to harvest visible and near-infrared (NIR) photons. A series of indoline-based unsymmetrical squaraine (SQ) dyes that contain alkyl chains at sp(3) C- and N- atoms of indoline moieties with a carboxylic acid anchoring group were synthesized. The optical and electrochemical properties of the SQ dyes in solution were nearly identical as there was no change in the D-A-D SQ framework; however, remarkable changes with respect to the power conversion efficiencies (PCE) were observed depending upon the position of alkyl groups in the dye. Introduction of alkyl groups to the indoline unit that was away from anchoring unit were helped in more dye loading with controlled organization of dyes on surface, increased charge transfer resistance, long electron lifetime, and hence higher PCE than that of the corresponding isomer in which the alkyl groups funtionalized indoline unit contains the carboxylic acid anchoring group. Careful analysis of incident photon-to current conversion efficiency (IPCE) profiles indicated the presence of aggregated structure on the TiO2 surface that contributes to the charge injection in the presence of a coadsorbent. A dye-sensitized solar cell (DSSC) device made out of SQ5 was achieved an efficiency of 9.0%, with an open-circuit potential (V-oc) of 660 mV and short-circuit current density (J(sc)) of 19.82 mA/cm 2, under simulated AM 1.5G illumination (100 mW/cm(2)). The IPCE profile of SQ5 shows an onset near to 750 nm with a good quantum efficiency (&gt;80%) in the range of 550-700 nm, indicating the importance of self-organization of dyes on the TiO2 surface for an efficient charge injection. This present investigation revealed the importance of position of alkyl groups in the squaraine-based dyes for the better PCE.</p>1 aAlagumalai, Ananthan1 aFairoos, Munavvar, M. K.1 aVellimalai, Punitharasu1 aSil, Manik, Chandra1 aNithyanandhan, Jayaraj  uhttps://library.ncl.res.in/content/effect-out-plane-alkyl-groups-position-dye-sensitized-solar-cell-efficiency-structure02322nas a2200229   4500008004100000022001400041245013200055210006900187260000800256300001200264490000800276520148200284653000901766653002101775653002001796653003001816653002501846100002401871700003901895700002701934856013101961       2019                        eng d  a0143-720800aEffect and position of spiro-bipropylenedioxythiophene pi-spacer in donor-pi-spacer-acceptor dyes for dye-sensitized solar cell0 aEffect and position of spirobipropylenedioxythiophene pispacer i  cFEB  a313-3230 v1613 a<p>Improper orientation and self-assembly of dyes on TiO2 surface are the main disadvantages at the dye-TiO2 interface that governs both charge injection and dye regeneration processes. In this report, a series of homo spiro-dimeric donor-pi-spacer-acceptor (D-pi-A) dyes based on bithiophene and terthiophene spacers with two-anchoring group containing dyes, TT1, T1T, TT1T were designed and synthesized by Pd-catalyzed successive Suzuki coupling followed by direct arylation reactions. The position of branching centre in TT1 and T1T was systematically varied, where the spiro unit was placed near and away from the anchoring carboxylic acid unit, respectively. The dimeric spiro-dye T1T showed device performance, which is 1.6 fold higher than its structural isomeric analogue TT1, of 3.9% with a V-oc and J(sc) of 0.593 V and 9.09 mA/cm2, respectively, whereas for the isomeric analogue TT1 a device performance of 2.45% (V-oc of 0.568 V and J(sc) of 6.25 mA/cm2) under simulated 1 Sun (100 mW/cm2) condition. The improved Voc for the dye T1T compared to TT1 dye was ascribed to the dipole moment exerted by the dyes on TiO2 surface. Further the PCE of 4.16% (V-oc 0.589 V, J(sc) 9.79 mA/cm2 respectively) maximum was observed, when an extra thiophene unit was inserted in between the donor and pi-spacer in dye TT1T. The shifting the position of branching spiroBiProDOT pi-spacer makes an impact on the device performance by synergistically enhancing both Voc and Jsc.</p>10aCDCA10aD-pi-A Spiro dye10aDye aggregation10adye-sensitized solar cell10aspiroBiProDOT spacer1 aSil, Manik, Chandra1 aKavungathodi, Munavvar, Fairoos Me1 aNithyanandhan, Jayaraj  uhttps://library.ncl.res.in/content/effect-and-position-spiro-bipropylenedioxythiophene-pi-spacer-donor-pi-spacer-acceptor-dyes