Micro-nano fabrication of hierarchical PPy/TiO2/Si by continuous self-assembly technology

Combining TiO2 with conducting polymer could enhance the photoelectric transformation efficiency of absorbed light, due to the formation of P-N heterojunctions. However, few people considered to increase the adsorption efficiency of incident light for the composites. In this manuscript, we demonstrate a facile approach of sequentially assembling TiO2 nanorods and polypyrrole (PPy) on the monocrystalline silicon wafer by the method of hydrothermal synthesis and chemical oxidation. The PPy/TiO2/Si composites with hierarchical structures possessed broadband antireflection and dual P-N heterojunctions, enhancing not only the incident light absorption efficiency but also the utilization efficiency of absorbed light. Thus, PPy/TiO2/Si with hierarchical structures is the excellent candidate materials for the photoelectric device and the photocatalyst.