Professor Xiong Yujie's research group at the University of Science and Technology of China has designed a flexible solar cell capable of photoelectric conversion in the near-infrared region, based on widely used semiconductor silicon material and employing a hot electron injection method using metal nanostructures. The research findings were recently published online in the leading international chemistry journal *Angewandte Chemie*.
Currently, most solar cells absorb visible light, leaving the near-infrared region, which accounts for 52% of sunlight, underutilized. To address this issue, Xiong Yujie's research group, building upon previous studies on semiconductor-metal interfaces, creatively integrated silver nanosheets with near-infrared light absorption properties with silicon nanowires to construct two different photovoltaic devices, both of which showed improved photoelectric conversion performance in the near-infrared region. Under near-infrared illumination, the hot electrons generated by the silver nanosheets can be directly injected into the silicon semiconductor, increasing the photoelectric conversion efficiency in this wavelength range by 59%.
Furthermore, traditional solar cells must be processed into rigid, plate-like objects, which limits their everyday applications. Flexible devices, on the other hand, are lightweight and can be folded, rolled, and adhered to curved surfaces, such as car windows, roofs, and clothing. Xiong Yujie's research group nanoscaled commercial silicon wafers and combined this with the near-infrared light absorption properties of silver nanosheets to create mechanically flexible near-infrared solar cells.
Experts say that this work has achieved a composite structure interface design with broad-spectrum light absorption by effectively combining two nanotechnology techniques: nanofabrication and nanosynthesis. It has also developed a simple and effective method for manufacturing near-infrared flexible solar cells, which is expected to be used in the development of smart temperature-controlled solar cells and wearable solar cells.
