03070nas a2200277   4500008004100000022001400041245013500055210006900190260000900259300001400268490000600282520203300288653002402321653002502345653003102370653003502401653005202436100002402488700002702512700002702539700001602566700002602582700003002608700002702638856012702665       2025                        eng d  a2574-096200aEffect of cyclization and alkyl group wrapping in visible-light-active unsymmetrical squaraine dyes for dye-sensitized solar cells0 aEffect of cyclization and alkyl group wrapping in visiblelightac  cAPR   a5017-50300 v83 a<p>
	A series of alkyl group-appended indoline- and carboxylic acid-functionalized indolenine-based visible-light-active unsymmetrical squaraine dyes, SQA7-10, were designed, synthesized, and utilized for the dye-sensitized solar cells device fabrication. The number of alkyl group has been increased systematically on the indoline moiety to control the self-assembly of dyes on TiO2 and to passivate the photoanode that helps in improving the open-circuit voltage (V-OC) by avoiding the charge recombination process. SQA7-10 dyes showed an absorption between lambda(max) 536-540 nm, with molar extinction coefficients of 1.62-2.13 x 10(5) M-1 cm(-1) in CH3CN. Further, ultraviolet-visible (UV-vis) studies on TiO2 indicated the formation of H-aggregated dyes (505-510 nm), which can be controlled by appending the alkyl groups. The energy levels of the highest occupied molecular orbital (HOMO) of these dyes are well aligned with the Nernst potentials of I-/I(3)(-)electrolyte and [Cu(tmby)(2)](+/2+) electrolytes with sufficient overpotentials required for the dye regeneration process. DSSC devices made with these dyes showed systematic enhancements of open-circuit voltage (V-OC) and device efficiency with respect to alkyl group incorporation for SQA7-10 with I-/I-3(-) electrolytes. All of the SQA dyes exhibited the device V-OC of more than 805 mV, where the introduction of alkyl groups systematically enhanced the V-OC in the order of SQA7 (805 mV) &lt; SQA8 (829 mV) &lt; SQA9 (843 mV) &lt; SQA10 (862 mV) without any addition of CDCA. Within the SQA dye series, SQA10 dye has achieved the highest DSSC device efficiency of 7.52% (J(sc) of 11.16 mA/cm(2), V-oc of 862 mV, and ff of 78%) with I-/I-3(-) electrolyte, whereas use of [Cu(tmby)(2)](+/2+) redox shuttle with SQA10 showed enhanced V-oc (1080 mV) and device efficiency (8.35%). The IPCE profile for the device fabricated with SQA dyes showed good response at 480 and 560 nm, which indicates the photocurrent generation from the aggregated structures.</p>
10aaggregation of dyes10acharge recombination10aDye-sensitized solar cells10aindoline and indolenine donors10avisible-light-activeunsymmetrical squaraine dye1 aJadhav, Avinash, P.1 aSingh, Ambarish, Kumar1 aShivankar, Bhavana, R.1 aSiby, Jesna1 aKrishnamurty, Sailaja1 aKrishnamoorthy, Kothandam1 aNithyanandhan, Jayaraj  uhttp://library.ncl.res.in/content/effect-cyclization-and-alkyl-group-wrapping-visible-light-active-unsymmetrical-squaraine02340nas a2200265   4500008004100000022001400041245011900055210006900174260000900243300001100252490000800263520140100271653002401672653001601696653003001712653002801742653001801770100002801788700003101816700001701847700002601864700003001890700002701920856012701947       2025                        eng d  a1010-603000aFar-red active squaraine dye-sensitized photoanode for dye-sensitized solar cells with a copper (II/I) electrolyte0 aFarred active squaraine dyesensitized photoanode for dyesensitiz  cFEB   a1160860 v4593 a<p>
	In dye-sensitized solar cells (DSSC), controlling the dye-aggregation on TiO2 and charge recombination between electrons present in TiO2 and electrolyte can be achieved by wrapping the long alkyl groups around the dye structure and further introducing bulky donor on the dye is a potential approach to enhance both the open-circuit potential and short-circuit current parameters. Additionally, bulky donor containing dye structures modulates the photophysical and electrochemical properties of the sensitizer which helps reducing the over potentials required for the dye regeneration process by utilizing a multidentate ligand containing [Cu(tme)]2+/+ and I- /I3redox electrolytes. Hagfeldt donor appended far-red NIR active unsymmetrical squaraine dye (SQ-HF) has been designed, synthesized, and characterized. SQ-HF dye showed an intense absorption at 676 nm (epsilon 1.7 x 105 M- 1cm- 1). Photophysical and electrochemical studies indicated that the LUMO and HOMO energy levels of the SQ-HF dye were suited for charge injection (from the LUMO of the dye to the conduction band of TiO2) and dyeregeneration processes, respectively. The DSSC device efficiency of 5.15 % (JSC of 10.83 mA/cm2 and VOC of 0.690 V) has been achieved for SQ-HF dye by utilizing a literature reported [Cu(tme)]2+/+ and 4.11 % (JSC of 8.74 mA/cm2 and VOC of 0.702 V) in I- /I3- redox shuttles, respectively.</p>
10aaggregation of dyes10aBulky donor10adye-sensitized solar cell10aPhotocurrent generation10asquaraine dye1 aNawghare, Indrajeet, S.1 aDeshmukh, Shivdeep, Suresh1 aJoshi, Krati1 aKrishnamurty, Sailaja1 aKrishnamoorthy, Kothandam1 aNithyanandhan, Jayaraj  uhttp://library.ncl.res.in/content/far-red-active-squaraine-dye-sensitized-photoanode-dye-sensitized-solar-cells-copper-iii