An Efficient Aniline-Based Co-Sensitizer for High Performance N3-Sensitized Solar Cells

Abstract

In this work, we report a comprehensive photovoltaic investigation of a structurally simple Donor-Acceptor (D?A) configured organic dye, N,N-PABA as an active co-sensitizer in DSSCs sensitized with well-known Ru (II) based N3 dye. This effective co-sensitizer (N,N-PABA) comprises N,N-dimethylaniline system as a donor scaffold linked with 4-aminobenzoic acid as an electron withdrawing functionality. In the present study, we have demonstrated the profound effect of concentration of sensitizer, i. e. N3 based dye as well as co-sensitizer, i. e. N,N-PABA on the photovoltaic performance characteristics of solar cells. Interestingly, the best photovoltaic performance was obtained for the co-sensitized device fabricated using 0.2 mM of N,N-PABA along with 0.3 mM of N3 sensitizer, in presence of 20 mM of CDCA. It displayed power conversion efficiency (PCE) of 5.82% with J<inf>SC</inf> of 14.35 mA.cm?2, V<inf>OC</inf> of 0.626 V and FF of 64.85%. Here, the N,N-PABA effectively filled the absorption valley, avoided the dye aggregation and reduced the charge recombination in the co-sensitized devices. Thus, the results ameliorate the role of efficient co-sensitizers to yield DSSC with improved performance by the selection of a matchable co-sensitizer at an appropriate concentration. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim