Architectural design of new conjugated systems carrying donor-pi-acceptor groups (carbazole-CF3): Characterizations, optical, photophysical properties and DSSC's applications

Abstract

In this study, two new organic dyes containing substituted N-octyl carbazole as electron donor and - CF3 units as electron acceptor group were designed and synthesized for ZnO-based dye sensitized solar cells (DSSCs). The synthesized carbazole derivatized compounds 3,6-bis(3,5-bis(trifluoromethyl)phenyl)9-octyl-9H-carbazole (IVa) and 3,6-bis(4-(trifluoromethyl)phenyl)-9-octyl-9H-carbazole (IVb) were characterized by FT-IR, H-1 NMR, C-13 NMR, HMBC and CHN analyses. The spectroscopic (UV-Vis and FL) and thermal properties (TGA-DTA) of these compounds were also investigated. The produced (IVa and IVb) ZnO films were used as photoanodes in all DSSCs. Microwave-assisted hydrothermal method was used to synthesize ZnO nanopowders with different morphologies which are used as photoanodes in DSSCs. The structural and morphological properties of ZnO nanopowders were investigated using X-ray diffraction (XRD) and field emission scanning electron microscopy (FESEM). ZnO-DSSCs were produced through coating ZnO nanopowders on transparent conductive fluorine-doped tin oxide (FTO) coated glass substrate using the Doctor Blade method. Current-voltage measurements of all produced DSSCs were carried out under a solar simulator with AM 1.5 G filter having an irradiance of 100 mW/cm(2). Solar cell performances of all DSSCs such as; open-circuit voltage (V-oc), short circuit current (J(sc)), fill factor (FF) and power conversion efficiency (PCE) were analyzed. (C) 2021 Elsevier B.V. All rights reserved.