A simple D-A-π-A configured carbazole based dye as an active photo-sensitizer: A comparative investigation on different parameters of cell

An organic photosensitizer (DP-1) with D-A-π-A architecture was systematically analyzed along with our previously reported dye N1. In the design, the dyes carry carbazole as donor, thiophene acetonitrile as π-spacer connected to varied acceptor/anchoring unit i.e., cyanoacrylic acid (N1) and 4-aminobenzoic acid (DP-1). Generally, cyanoacrylic acid and carboxyl groups have been investigated extensively as effective electron acceptor/anchoring unit for the design of the sensitizer for dye-sensitized solar cells (DSSC) application and displayed superior photon conversion efficiency. In the present work, both the dyes were taken up for various studies focusing on photophysical, electrochemical, theoretical and photovoltaic investigation in the corresponding solar cells. From the photophysical and electrochemical studies it was established that, the both dyes show upright thermodynamic feasibility for electrochemical processes in the cell i.e., both electron and dye regeneration. Also, the DFT studies appends the existence of feasible HOMO-LUMO charge distribution. Finally, the devices fabricated by employing these dyes as sensitizer with 10 mM DCA as co-adsorbent. The device based on N1 displayed improved photon conversion efficiency compared to the cell sensitized using DP-1. This work may provide a new strategy for designing efficient photosensitizers to further ameliorate the DSSCs performance.