Faculty Publications
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Item Highly efficient carbazole based co-sensitizers carrying electron deficient barbituric acid for NCSU-10 sensitized DSSCs(Elsevier Ltd, 2018) Naik, P.; Keremane, K.S.; Elmorsy, M.R.; Su, R.; El-Shafei, A.; Vasudeva Adhikari, A.V.Herein, we report a comparative study of four interesting metal-free carbazole based organic dyes with different structural configurations, carrying electron deficient barbituric acid (C1-4), as effective co-sensitizers in DSSCs sensitized with NCSU-10 dye. The new entities comprise different structural architectures, viz. D-A (C1), D-?-A (C2), D-D-?-A (C3) and D-A-?-A (C4) configurations with same accepting/anchoring moiety. They consist of carbazole as donor scaffold linked to barbituric acid as an acceptor/anchoring unit via different ?-spacers. This paper describes the study of all the four co-sensitizers with regard to their structural, photophysical, electrochemical, theoretical and photovoltaic investigations. Also, it includes their structure-performance correlation study in detail. The devices co-sensitized with C1-4 displayed the superior photovoltaic performance when compared to NCSU-10 alone. The results ameliorate the role of efficient co-sensitizers to yield DSSC with improved performance. © 2018 Elsevier LtdItem Improvement in performance of N3 sensitized DSSCs with structurally simple aniline based organic co-sensitizers(Elsevier Ltd, 2018) Naik, P.; Abdellah, I.M.; Abdel-Shakour, M.; Su, R.; Keremane, K.S.; El-Shafei, A.; Vasudeva Adhikari, A.V.In this work, we report comprehensive photovoltaic investigation of four structurally simple D-A configured organic dyes, A1-4 as active co-sensitizers in DSSCs sensitized with well-known Ru (II) based N3 dye. These effective co-sensitizers (A1-4) comprise N,N-dimethylaniline ring as donor scaffold linked with electron withdrawing functionalities, viz. barbituric acid (A1), N,N-dimethyl barbituric acid (A2), thiobarbituric acid (A3), and N,N-diethyl thiobarbituric acid (A4) as acceptor/anchoring units. In the present study, for the first time we have demonstrated the profound role of various simple organic molecules carrying different heterocyclic anchoring units on the photovoltaic parameters of the N3 sensitized devices. Also, the effect of concentration of sensitizer/co-sensitizers on the device performance characteristics has been investigated in depth. From the results, it is evident that, the device fabricated using co-sensitizer A2 carrying N,N-dimethyl barbituric acid along with sensitizer N3 in all concentrations outperformed when compared to N3 alone or other co-sensitizers. Interestingly, the best photovoltaic performance was obtained for the co-sensitized device fabricated using 0.3 mM co-sensitizer A2 along with 0.2 mM of N3 sensitizer. It displayed PCE of 7.02% with JSC of 15.27 mA·cm?2, VOC of 0.671 V and FF of 68.47%. Thus, the observed results have thrown new light upon the device optimization to yield DSSCs with improved performance by the selection of matchable co-sensitizers at appropriate concentrations. © 2018 Elsevier LtdItem Simple thiophene-bridged D-?-A type chromophores for DSSCs: a comprehensive study of their sensitization and co-sensitization properties(Royal Society of Chemistry, 2020) Keremane, K.S.; Abdellah, I.M.; Naik, P.; El-Shafei, A.; Vasudeva Adhikari, A.V.Herein, we report the design and synthesis of four new thiophene-bridged D-?-A configured organic dyes T1-4 comprising different donors, ?-spacers and anchoring units, as potential sensitizers and co-sensitizers for DSSCs. The current work also highlights their structural, photophysical, thermal, electrochemical, theoretical, and photoelectrochemical studies, including evaluation of their structure-property relationships. The optical results revealed that the dyes T1-4 display ?abs and ?emi in the range of 402-461 nm and 556-575 nm, respectively, with a bandgap in the order of 2.31-2.58 eV. Furthermore, the results showed that the dyes possess all the pre-requisites to act as sensitizers/co-sensitizers. Among the tested dyes, the device based on sensitizer T2 achieved the highest PCE compared to the other three dyes, under the standard conditions. Furthermore, their co-sensitized devices were fabricated by co-adsorbing them with the well-known Ru-based MH-12 sensitizer and interestingly the co-sensitizer T3 carrying an alkoxy group and a barbituric acid anchor displayed the highest PCE of 8.79%, which is much higher than that of MH-12 alone (8.18%). Conclusively, the study furnishes a deeper understanding of the intricacies involved in the structural modification of sensitizers/co-sensitizers in achieving an enhanced performance of the devices. This journal is © 2020 the Owner Societies.Item Enhancing the Photoelectrochemical Performance of Ru(II)-Sensitized Dye-Sensitized Solar Cells Using Cyanopyridine-Based Cosensitizers(John Wiley and Sons Inc, 2025) Naik, P.; Abdellah, I.M.; Abdel-Shakour, M.; Keremane, K.S.; Vasudeva Adhikari, A.V.The cosensitization approach is one of the widely adopted strategies for systematically enhancing photovoltaic performance of dye-sensitized solar cells (DSSCs) by utilizing two or more dyes with distinct absorption spectra. This method achieves panchromatic absorption, improves intramolecular charge transfer performance, prevents dye aggregation, and increases dye loading capability. In this study, we investigated four previously reported push–pull-type dianchored chromophores (CP1–4) featuring a cyanopyridine scaffold as cosensitizer to enhance the performance of Ru(II)-based N3-sensitized DSSCs. Both the co-sensitized devices (N3 + CP1–4) and the N3-only devices were fabricated using a fixed dye concentration of 0.2 mM for each sensitizer/cosensitizers, while the coadsorbent chenodeoxycholic acid (CDCA) was systematically varied between 0 and 20 mM. This systematic variation of CDCA concentration was designed to examine its role in suppressing dye aggregation and modulating interfacial charge dynamics. Among the Series, CP4, carrying a thiobarbituric acid anchoring/acceptor group, demonstrated superior performance at all CDCA concentrations, achieving power conversion efficiency of 6.67%, 6.79%, and 5.74%, compared to 6.02%, 6.10%, and 5.44% for devices sensitized with N3 alone. Further, electrochemical impedance spectroscopy measurements confirmed the improved charge transport and reduced recombination in these devices. These findings highlight the potential of rationally engineered cosensitizers and optimized coadsorbent concentrations for enhancing the performance of metal-based sensitizers in DSSCs. © 2025 Wiley-VCH GmbH.