@article {49614,
	title = {Double anchoring squaraine dye with triazatruxene amine donor for dye-sensitized solar cells: sequential cosensitization for panchromatic light-harvesting},
	journal = {Journal of Photochemistry and Photobiology A-Chemistry},
	volume = {462},
	year = {2025},
	month = {MAY},
	pages = {116229},
	type = {Article},
	abstract = {<p>
	Dyes are firmly bound to a semiconducting TiO2 film using carboxylic acid anchoring groups for an efficient electron transfer from the excited state of dye to the conduction band (CB) of TiO2. Strong dye binding can be accomplished with multi-anchoring dye designs to improve photophysical characteristics, including high extinction coefficients, panchromatic absorption, post-sensitization modifications, and dark current suppression, besides enhancing the stability of the dye-TiO2 interface. Herein, a novel KV2D dye with double squaraine acceptor and double carboxylic acid anchoring groups is designed to achieve a high extinction coefficient (epsilon, 3.57 x 105M-1cm-1) and robust binding to the TiO2 film for an effective electron transfer. We systematically changed the amount of coadsorbent chenodeoxycholic acid (CDCA) to control the aggregation of dyes on the TiO2 surface that improves the power conversion efficiency (PCE, eta) for the devices based on the doubleanchoring KV2D. Out of these devices, KV2D: CDCA (1:10) based cell exhibited the best PCE of 5.26\% with VOC of 754 mV, JSC of 10.41 mA/cm2, and ff of 67\%. The sequential cosensitization studies were carried out with a far-red active dye to find the effect of the strong binding of the sensitizer to the TiO2 film. Interestingly, when di-anchoring, KV2D was sensitized first for 12 h and then sequentially cosensitized with far-red absorbing SQS4 for 5 h to achieve a PCE of 5.0\% with VOC of 697 mV, JSC of 10.23 mA/cm2, and ff of 70\% with panchromatic spectral response in IPCE upto 730 nm giving higher photocurrent generation.</p>
},
	keywords = {aggregation of dyes, Bulky donor unit, Double acceptor dye, Dye-sensitized solar cells, self-assembly of dye, squaraine dyes, triazatruxene},
	issn = {1010-6030},
	doi = {10.1016/j.jphotochem.2024.116229},
	author = {Ingole, Kiran Balaso and Siby, Jesna and Pandya, Rinu and Vanka, Kumar and Krishnamoorthy, Kothandam and Nithyanandhan, Jayaraj}
}
@article {49516,
	title = {Effect of cyclization and alkyl group wrapping in visible-light-active unsymmetrical squaraine dyes for dye-sensitized solar cells},
	journal = {ACS Applied Energy Materials},
	volume = {8},
	year = {2025},
	month = {APR },
	pages = {5017-5030},
	type = {Article},
	abstract = {<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>
},
	keywords = {aggregation of dyes, charge recombination, Dye-sensitized solar cells, indoline and indolenine donors, visible-light-activeunsymmetrical squaraine dye},
	issn = {2574-0962},
	doi = {10.1021/acsaem.4c03116},
	author = {Jadhav, Avinash P. and Singh, Ambarish Kumar and Shivankar, Bhavana R. and Siby, Jesna and Krishnamurty, Sailaja and Krishnamoorthy, Kothandam and Nithyanandhan, Jayaraj}
}
