New natural dyes extracted by ultrasonic and soxhlet method: Effect on dye-sensitized solar cell photovoltaic performance

Abstract

This study employed soxhlet and ultrasonic methods to extract novel natural dyes from Rhamnus tinctoria seed, Rubia fruticosa fruits, and Pinus pinea bark, which were then used as sensitizers in dye-sensitized solar cells (DSSCs). XRD data showed that TiO2 in the photoanode layer was in the anatase phase. The produced DSSCs were assessed for photovoltaic performance and electrochemical charge transfer while sensitizing dyes were characterized using UV–vis spectroscopy and FTIR. Natural dyes leached with different extraction methods showed different absorption behaviors in the UV–vis region. FTIR results revealed the presence of both carbonyl and hydroxyl groups, which enhanced the interaction between the extracted dyes and the TiO2 thin film. All cells using sensitizers obtained by the Soxhlet method showed higher efficiency compared to the ultrasonic method. The highest cell performance (ɳ = 0.47%) was obtained with 0.71 V Voc, 0.92 mA/cm2 Jsc, and 0.72 FF for the sensitizer extracted from Rhamnus tinctoria seeds by the soxhlet method.