Abstract
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•Three novel organic sensitizers based on different donor groups substituted with similar bridge and acceptor moieties.•The B2 sensitizer contains highly conjugated and strong electron withdrawing group (pyrene) was substituted.•The B2 sensitizer exhibited 6.23% efficiency under 100 mW.cm2 light illumination.•The high performance device having stability up to 700 h, under continuous 1 sun light illumination.
In the present work, we have synthesized three novel organic sensitizers, based on various donor groups which are in conjugation with similar bridge and acceptor moieties. We have studied the effect of donor groups with common bridge and anchoring group sensitizers on optical, electrochemical, dye sensitized solar cell’s performance and electron transfer interface properties as well. We have also represented systematically analysis of influence of donor groups in structural geometry, energy distribution and energy-transfer from HOMO to LUMO by density functional theory. The B2 sensitizer contains highly conjugated, strong electron withdrawing group and electron transfer form donor group to anchoring group happens much more rapid in it compared to other two sensitizers. However, B2 sensitizer has exhibited 6.23% efficiency under 1 sun light illumination. The influence of donor groups on device performance was clearly shown on IPCE spectrum as well. The studied effect of chenodeoxycholic acid (CDCA) in a sensitizer’s solution as a co-absorbent on the DSSCs performance and exhibited highest efficiency (6.68%). We found that co-absorbent can be hinder the sensitizer aggregation and rise electron injection yield and thus short circuit current (Jsc). The device interface kinetics was studied by electrochemical impedance spectroscopy and calculated electron lifetime, interface charge transfer resistance and recombination resistance by fitted equivalent circuit. Moreover, we have checked high performance device stability up to 700 h, under continuous 1 sun light illumination.