Abstract

The use of natural dyes as photosensitizers has several advantages including their easy extraction and their biodegradable, nontoxic, and environmentally friendly nature, which makes them vital for application in dye-sensitized solar cells (DSSC). In the present work, we study the effects of extraction solvent on the photovoltaic performance of a natural dye sensitizer for TiO₂-based DSSC. Extracts of Tecoma stans flowers in two different solvents, ethanol and ethanol–water mixture, were used as the dye sensitizer for extending the spectral sensitivity of TiO₂. The optical properties of the dye extracts were studied by their UV–visible absorption spectra. Fourier transform infrared spectra revealed the presence of anchoring groups and coloring pigments, and nuclear magnetic resonance spectroscopy and mass spectrometry were used to characterize the main constituents of the dye extract. The photovoltaic characteristics of these dye extracts coated on TiO₂ were investigated by employing them as DSSC photoanodes. With the dye extracted in ethanol and coated on TiO₂, an open-circuit voltage (V_oc) of 0.293 V, short-circuit photocurrent density (J_sc) of 0.790 mA/cm², fill factor (FF) of 0.46, and conversion efficiency (η) of 0.13% were obtained, whereas dye extracted in the ethanol–water mixture revealed V_oc of 0.285 V, J_sc of 0.735 mA/cm², FF of 0.37, and η of 0.09%. The photovoltaic performance of the dye extracts in the two cases underlines the greater effectiveness of ethanol as dye extraction solvent.

Graphical Abstract

中文翻译：

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染料提取溶剂对Tecoma stans致敏太阳能电池光伏性能的影响

摘要

天然染料作为光敏剂的使用具有许多优势，包括易于提取，可生物降解，无毒且对环境友好的特性，这使其在染料敏化太阳能电池（DSSC）中的应用至关重要。在本工作中，我们研究了萃取溶剂对TiO ₂基DSSC天然染料敏化剂的光电性能的影响。在两种不同溶剂（乙醇和乙醇-水的混合物）中提取的Tecoma stans花提取物用作染料敏化剂，以扩展TiO ₂的光谱敏感性。染料提取物的光学性质通过其紫外可见吸收光谱进行了研究。傅立叶变换红外光谱揭示了锚固基团和着色颜料的存在，并使用核磁共振波谱和质谱法表征了染料提取物的主要成分。通过将它们用作DSSC光阳极，研究了这些涂覆在TiO ₂上的染料提取物的光电特性。将染料萃取到乙醇中并涂在TiO _2上，开路电压（V _oc）为0.293 V，短路光电流密度（J _sc）为0.790 mA / cm ²，填充系数（FF）为0.46，并且转换效率（η）获得0.13％的），而从乙醇-水混合物中提取的染料显示V _oc为0.285 V，J _sc为0.735 mA / cm ²，FF为0.37，η为0.09％。在这两种情况下，染料提取物的光电性能突出了乙醇作为染料提取溶剂的更大效力。

图形概要