molecules Article A Combined Experimental and Computational Study of Chrysanthemin as a Pigment for Dye-Sensitized Solar Cells Atoumane Ndiaye 1,2 , Alle Dioum 1, Corneliu I. Oprea 2 , Anca Dumbrava 3,* , Jeanina Lungu 2, Adrian Georgescu 2, Florin Moscalu 2, Mihai A. Gîr¸tu 2,* , Aboubaker Chedikh Beye 1 and Issakha Youm 1,* 1 Department of Physics, Cheikh Anta Diop University of Dakar, 5005 Dakar-Fann, Senegal;
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[email protected] (I.Y.) Abstract: The theoretical study of chrysanthemin (cyanidin 3-glucoside) as a pigment for TiO2-based dye-sensitized solar cells (DSSCs) was performed with the GAUSSSIAN 09 simulation. The electronic spectra of neutral and anionic chrysanthemin molecules were calculated by density functional theory with B3LYP functional and DGDZVP basis set. A better energy level alignment was found for partially deprotonated molecules of chrysanthemin, with the excited photoelectron having enough energy in order to be transferred to the conduction band of TiO2 semiconductor in DSSCs. In addition, we used the raw aqueous extracts of roselle (Hibiscus sabdariffa) calyces as the source of chrysanthemin Citation: Ndiaye, A.; Dioum, A.; and the extracts with various pH values were tested in DSSCs.