Cosensitization of Structurally Simple Porphyrin and Anthracene-Based Dye for Dye-Sensitized Solar Cells

Abstract

Since their introduction, dye-sensitized solar cells (DSCs) have achieved huge success at a laboratory level. Recently, research is concentrated to visualize large DSC modules at the commercial platform. In that aspect, we have tested structurally simple porphyrin-based dye SK6 and anthracene-based dye CW10 for DSCs application under simulated 1 sun (AM 1.5G) and indoor light sources. These two dyes can be easily synthesized and yet are efficient with cell performances of ca. 5.42% and ca. 5.75% (without coadsorbent/additive) for SK6 and CW10, respectively, under AM 1.5G illumination. The power conversion efficiency (PCE) of SK6 reported in this work is the highest ever reported; this is achieved by optimizing the adsorption of SK6 on TiO₂ photoanode using the most suitable solvent and immersion period. Cosensitization of SK6 with CW10 on TiO₂ surface has boosted cell performance further and achieved PCE of ca. 6.31% under AM 1.5G illumination. Charge-transfer properties of individual and cosensitized devices at TiO₂/dye/electrolyte interface were examined via electrochemical impedance spectroscopy. To understand the cell performances under ambient light conditions, we soaked individual and cosensitized devices under T5 and light-emitting diode light sources in the range of 300-6000 lx. The PCE of ca. 22.91% under T5 light (6000 lx) with J_SC = 0.883 mA cm^-2, V_OC = 0.646 V, and FF = 0.749 was noted for the cosensitized device, which equals a power output of 426 μW cm^-2. These results reveal that DSCs made of structurally simple dyes performed efficiently under both 1 sun (AM 1.5G) and indoor light conditions, which is undoubtedly a significant achievement when it comes to a choice of commercial application.