Faculty Publications

Now showing 1 - 3 of 3

Molecular Engineering and Theoretical Investigation of Novel Metal-Free Organic Chromophores for Dye-Sensitized Solar Cells
(Elsevier Ltd, 2015) Babu, D.D.; Cheema, H.; Elsherbiny, D.; El-Shafei, A.; Vasudeva Adhikari, A.V.
In this work we report design and synthesis of three new metal free D-D-A-?-A type dyes (E1-3) with different acceptor/anchoring groups, as effective sensitizers for nanocrystalline titanium dioxide based dye sensitized solar cells. All the three dyes carry electron donating methoxy group as an auxiliary and indole as a principal donor, cyanovinylene as an auxiliary acceptor and thiophene as a ?-spacer. Whereas, cyanoacetic acid, rhodanine-3-acetic acid and 4-aminobenzoic acid perform as acceptor/anchoring moieties, respectively in the dyes E1-3. Though the dye containing 4-aminobenzoic acid unit (E3) exhibits comparatively lower ?max, it shows the highest power conversion efficiency arising from the higher electron life time and good light-harvesting capability. The DFT studies reveal a better charge separation between the HOMO and LUMO levels of E3, further substantiating the experimental results. Among the three dyes, E3 shows the best photovoltaic performance with short-circuit current density (Jsc) of 9.35 mA cm-2, open-circuit voltage (Voc) of 620 mV and fill factor (FF) of 0.71, corresponding to an overall conversion efficiency of 4.12% under standard global AM 1.5G. © 2015 Elsevier Ltd. All rights reserved.
From Molecular Design to Co-sensitization; High performance indole based photosensitizers for dye-sensitized solar cells
(Elsevier Ltd, 2016) Babu, D.D.; Su, R.; El-Shafei, A.; Vasudeva Adhikari, A.V.
Herein, we report the molecular design and synthesis of two novel organic co-adsorbers DBA-1((Z)-2-cyano-3-(5-(4-(cyclohexa-1,5-dien-3-ynyl(phenyl)amino)phenyl)-1-hexyl-1H-indol-3-yl)acrylic acid) and (DBA-2) 5-((5-(4-(diphenylamino)phenyl)-1-hexyl-1H-indol-3-yl)methylene)pyrimidine-2,4,6(1H,3H,5H)-trione with D-D-A (donor-donor-acceptor) architecture. We have combined the strong electron donating triphenylamine group with indole moiety attached to different acceptors/anchoring groups, as co-adsorbers for dye-sensitized solar cells and we present for the first time, the role of anchoring/acceptor unit on their co-adsorption properties. In this study, cyanoacetic acid and barbituric acid are employed as anchoring groups in the co-sensitizers DBA-1 and DBA-2, respectively. Their electrochemical and photo-physical properties along with molecular geometries, obtained from Density Functional Theory (DFT) are employed to vindicate the effect of co-sensitizer structures on photovoltaic properties of DSSCs. We have demonstrated that the co-sensitization effect is profoundly dependent upon the anchoring/acceptor unit in the co-adsorber molecule. Devices co-sensitized using DBA-1 and DBA-2 along with HD-2 (Ru-complex of 4, 4?-bis-(1,4-benzodioxan-5-yl-vinyl)-[2,2?]bipyridine), displayed higher power conversion efficiencies (PCEs) than the device sensitized using only HD-2. In the present work, ruthenium based sensitizer, HD-2, has been chosen due to its better solar-to-power conversion efficiency and impressively higher photocurrent densities than that of standard N719. Among them, co-adsorber DBA-2, containing barbituric acid as the acceptor/anchoring group displays promising photovoltaic results and exhibited an enhanced efficiency of 8.06%. Further, good agreement between the calculated and experimental results showcase the precision of the energy functional and basis set utilized in this study. All these findings provide a deeper insight and better understanding into the intricacies involved in the design of superior co-sensitizers for development of highly efficient DSSCs. © 2016 Elsevier Ltd. All rights reserved.
A simple D-A-?-A configured carbazole based dye as an active photo-sensitizer: A comparative investigation on different parameters of cell
(Elsevier B.V., 2020) Babu, D.D.; Naik, P.; Keremane, K.S.
An organic photosensitizer (DP-1) with D-A-?-A architecture was systematically analyzed along with our previously reported dye N1. In the design, the dyes carry carbazole as donor, thiophene acetonitrile as ?-spacer connected to varied acceptor/anchoring unit i.e., cyanoacrylic acid (N1) and 4-aminobenzoic acid (DP-1). Generally, cyanoacrylic acid and carboxyl groups have been investigated extensively as effective electron acceptor/anchoring unit for the design of the sensitizer for dye-sensitized solar cells (DSSC) application and displayed superior photon conversion efficiency. In the present work, both the dyes were taken up for various studies focusing on photophysical, electrochemical, theoretical and photovoltaic investigation in the corresponding solar cells. From the photophysical and electrochemical studies it was established that, the both dyes show upright thermodynamic feasibility for electrochemical processes in the cell i.e., both electron and dye regeneration. Also, the DFT studies appends the existence of feasible HOMO-LUMO charge distribution. Finally, the devices fabricated by employing these dyes as sensitizer with 10 mM DCA as co-adsorbent. The device based on N1 displayed improved photon conversion efficiency compared to the cell sensitized using DP-1. This work may provide a new strategy for designing efficient photosensitizers to further ameliorate the DSSCs performance. © 2020 Elsevier B.V.

Faculty Publications

Browse

Filters

Settings

Sort By

Results per page

Search Results