Design and photovoltaic studies of W@TiO 2 /rGO nanocomposites with polymer gel electrolyte

The present research endeavor is focused on designing tungsten( vi ) ion-doped TiO 2 /rGO nanocomposites (TR NCs) via a single-step in situ wet chemical route for Co 2+ /Co 3+ -based PEO–PEG polymer gel electrolyte-assisted D–π–A carbazole dye (SK3) sensitized solar cells (DSSCs). After the synthesis of the desired W@TiO 2 /rGO (WTR) NCs, their physicochemical ( viz. , optoelectrical, structural, morphological, electrochemical, etc. ) properties are studied. BET reveals a higher surface area with improved pore volumes up to 344.04 m 2 g −1 and 0.918 cm 3 g −1 , respectively, for W 0.020 @Ti 0.980 /rGO (WTR-2) NCs as compared to others. The doctor blade technique is deployed for depositing photoanodes. EIS and M–S analysis showed improved photogenerated charge transfer and a higher carrier density, respectively, for WTR-2 NCs. Thereafter, WTR-2 NCs were further sensitized with SK3 dye and sandwiched with a Pt-counter electrode for making DSSCs, and then photovoltaic performance was studied and compared to that of bare TiO 2 NPs under an AM 1.5 solar simulator. The WTR-2 NC-based DSSCs exhibited the highest conversion efficiency ( η ) of 6.95%, which is 3.7 and 5.2 times greater than that of TR NC-based (1.84%) and bare TiO 2 NP-based (1.32%) DSSCs, respectively. Hence, the present investigation validates the effectual photovoltaic performance of the DSSCs comprising TiO 2 NP-based hybrids and SK3 dye and the utilization of Co 2+ /Co 3+ -based PEO–PEG polymer gel electrolyte.