02581nas a2200265   4500008004100000022001400041245010200055210006900157260000800226300001600234490000700250520165100257653003101908653002401939653003001963653001901993653003002012653001902042100001802061700002402079700003902103700001902142700002702161856012702188       2018                        eng d  a1944-824400aFused fluorenylindolenine-donor-based unsymmetrical squaraine dyes for dye-sensitized solar cells0 aFused fluorenylindoleninedonorbased unsymmetrical squaraine dyes  cAUG  a26335-263470 v103 a<p>A series of four unsymmetrical squaraine dyes, XSQ1-4, were synthesized using a fused fluorenylindolenine-based donor unit for dye-sensitized solar cells (DSSCs). The fused structure of fluorenylindolenine helped in moving the absorption toward the near-infrared (NIR) region, and the two sp(3)-C centers available on this donor were utilized to incorporate out-of-plane alkyl chains in opposite directions to control the dye-dye interactions on the TiO2 surface. High extinction coefficient (epsilon &gt;= 10(5) M-1 cm(-1)) for absorbing NIR photons and suitable highest occupied molecular orbital and lowest unoccupied molecular orbital energy levels with respect to the conduction band of TiO2 and electrolyte for charge injection and dye regeneration processes, respectively, make these dyes potential sensitizers for DSSCs. Introduction of branched alkyl groups in the pi-framework helped in controlling dye aggregation to reduce exciton quenching and assisted in TiO2 surface passivation to avoid the charge recombination process. Furthermore, having a naphthyl group on the indole part of the anchoring group containing segment helped to red-shift the absorption spectrum of dyes 15 nm toward the NIR region (XSQ3-4). Among all of the dyes under investigation, XSQ2 gave the best photovoltaic performance, having a short-circuit current density (J(SC)) of 13.99 mA cm(-2), open -circuit voltage (V-OC) of 0.66 V, and a fill factor (ff) of 0.71, with a device performance (eta) of 6.57%. Electrochemical impedance spectroscopy revealed higher electron lifetime on TiO2 for XSQ2, which helps to avoid the charge recombination process.</p>10aDye-sensitized solar cells10afluorenylindolenine10aH- and J-type aggregation10aNIR absorption10aout-of-plane alkyl groups10asquaraine dyes1 aBisht, Rajesh1 aSudhakar, Vediappan1 aKavungathodi, Munavvar, Fairoos Me1 aKarjule, Neeta1 aNithyanandhan, Jayaraj  uhttps://library.ncl.res.in/content/fused-fluorenylindolenine-donor-based-unsymmetrical-squaraine-dyes-dye-sensitized-solar02341nas a2200265   4500008004100000022001400041245011900055210006900174260000900243300001100252490000800263520140100271653002401672653001601696653003001712653002801742653001801770100002801788700003101816700001701847700002601864700003001890700002701920856012801947       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  uhttps://library.ncl.res.in/content/far-red-active-squaraine-dye-sensitized-photoanode-dye-sensitized-solar-cells-copper-iii