Amplifying performance through co-sensitization of Acrylamide/2-Pyridone dyes in DSSCs

In this research, we synthesized new organic dyes, called BS-1–8, based on acrylamide/2-pyridone for use in dye-sensitized solar cells (DSSCs). These dyes were designed with a D-π-A configuration and underwent molecular engineering to fine-tune their spectral properties and energy levels. Through a comprehensive analysis combining experimental and theoretical approaches, we investigated various aspects of these dyes, including their optical, electrochemical, photovoltaic, geometrical, and electronic features. The newly developed dyes exhibited strong absorption in the UV–visible range, characterized by high molar extinction coefficients. Upon sensitization with BS-1–8, the efficiency of DSSCs ranged from 2.83 % to 5.01 %. Acrylamide-based sensitizers (BS-1–4) achieved efficiencies ranging from 3.82 % to 5.01 %, while 2-pyridone-based sensitizers (BS-5–8) scored between 2.83 % and 3.57 %. Notably, when co-sensitized with N719 at concentrations of 0.2–0.3 mM, the DSSCs showed a significant increase in power conversion efficiencies (PCEs) ranging from 7.85 % to 9.01 %, compared to 7.50 % for DSSCs sensitized with N719 alone. Specifically, the performance of 0.2 mM BS-4 was 20 % better than that of N719. This improvement in PCEs can be attributed to the enhanced Voc (open-circuit voltage) achieved through co-sensitization, highlighting the potential benefits of using sensitizers to develop more efficient DSSCs. The highest achieved PCE was 9.01 %, accompanied by a Jsc (short-circuit current density) of 20.07 mA.cm−2 and a Voc of 0.732 V for the mixed co-sensitizers (0.2 mM BS-4 + 0.2 mM N719). These findings indicate that the combination of co-sensitization is a promising strategy for developing efficient D-π-A-type sensitizers and evaluating DSSC performance. Additionally, the study of incident photon-to-current efficiency (IPCE) and electrochemical impedance spectroscopy (EIS) provided insights into the mechanisms contributing to these improvements. Overall, these results suggest that BS-1–8 sensitizers have significant potential for advancing the development of more efficient DSSCs.