Innovating dye-sensitized solar cells: Thiazole-based Co-sensitizers for enhanced photovoltaic performance with theoretical insights

Abstract

This investigation outlines the synthesis and design of four innovative organic dyes (MRS-1-4) as co-sensitizers for dye-sensitized solar cells (DSSCs), which are co-sensitized with the well-established Ru (II) dye N719. These new dyes incorporate an electron-rich furan unit attached with thiazole as auxiliary acceptors that linked into electron-withdrawing/anchoring groups, such as carboxylic and nitro groups, which enhances the photovoltaic performance of the cells. We conducted a thorough characterization of the co-sensitizers using a variety of techniques and evaluated their photovoltaic performance by analyzing their optical and electrochemical parameters, as well as their molecular geometries derived from density functional theory (DFT) calculations. To increase the efficiency of DSSCs, we co-sensitized the MRS-1-4 dyes with N719, which led to a significant improvement in the power conversion efficiency (PCE) of the cells. The DSSC fabricated using MRS-4 dye as a co-sensitizer with N719 attained a remarkable PCE of 8.13%, with an impressive short-circuit current density (JSC) of 19.50 mA cm−2, open-circuit voltage (VOC) of 0.65 V, and fill factor (FF) of 64.18%, while the single-DSSC device with N719 e exhibited a PCE of 7.50%, with JSC of 17.99 mA cm−2, VOC of 0.69 V, and FF of 60.42%. In addition, we performed theoretical characterization of the co-sensitizers using time-dependent DFT, which was in excellent agreement with the experimental results. Our findings demonstrate that the MRS-1-4 co-sensitizers are highly promising candidates for the development of efficient DSSCs and provide valuable insights into the design and optimization of co-sensitizers for enhanced photovoltaic performance.