Abstract

The global increase in energy consumption, driven by continuous technological development and the urgent need to mitigate the rise in the Earth's overall energy, primarily caused by petroleum-derived energy sources, has spurred an ongoing search for renewable and clean energy alternatives. A prime example is photovoltaic solar energy, which stands out due to its abundance and significant energy potential. However, conventional siliconbased photovoltaic devices do not effectively utilize all available surfaces due to their high rigidity, which represents a substantial limitation in terms of design flexibility and the development of green building applications. In this context, dye-sensitized solar cells (DSSCs) represent a low-cost, flexible, sustainable, and easily manufactured alternative, enabling decentralized and adaptive photovoltaic applications that support the development of sustainable energy architecture. This study developed a novel eco-friendly dye-sensitized solar cell (DSSC) through the incorporation of silver nanoparticles (AgNPs) biosynthesized via a green chemistry approach using Aristotelia chilensis (maqui) extract. The synthesis process was systematically optimized by varying the concentration of silver nitrate (AgNO3), the percentage of Aristotelia chilensis extract, and the reaction time. The resulting nanoparticles were characterized using UV-Vis spectroscopy, transmission electron microscopy (TEM), and X-ray photoelectron spectroscopy (XPS). The integration of Aristotelia chilensis-derived AgNPs into the DSSCs significantly improved optical absorption within the visible range. Under standard testing conditions (AM1.5G; 25 degrees C; 1000 W/m2), a concentration of 15 mg/L AgNPs increased the short-circuit current density by 70 % and doubled the energy conversion efficiency compared to control devices. Electrochemical impedance spectroscopy (EIS) further demonstrated that a concentration of 15 mg/L AgNPs based on Aristotelia chilensis extract effectively reduced charge transfer resistance at the TiO2/Aristotelia chilensis/electrolyte interface.