Dual‐Enhanced Effect of Ionic Liquid Incorporation on Improving Hybrid Harvesting Properties of Solar and Raindrop Energy

Abstract Ubiquitous environmental energy has become an important energy source for ensuring long‐lasting operation of unattended monitoring systems. However, several technical bottlenecks remain for achieving improved collection performance of environmental energy. Herein, a transparent composite film comprising micro‐pyramid arrays (mp‐arrays) and a conductive ionic liquid (IL) based on polydimethylsiloxane (PDMS) is innovatively generated as a difunctional layer that acts as an antireflective coating for solar cells and an enhanced triboelectric layer for the raindrop‐harvesting triboelectric nanogenerator (RH‐TENG). The regular mp‐arrays fabricated using the template transfer technology according to the matched refractive index between IL and PDMS effectively inhibit the surface reflection and improve the light trapping ability of solar cells. Owing to a significant increase in transmittance, the power conversion efficiency of the solar cell is enhanced by 10.92% owing to the IL@PDMS coating with mp‐arrays (mp‐IL@PDMS). Further, the conductive IL significantly improves the dielectricity of PDMS film. Due to the improved dielectric constant, increased aspect ratio, and excellent hydrophobicity, the output voltage and current of the RH‐TENG with mp‐IL@PDMS are enhanced by ≈24‐ and 44‐fold, respectively. Overall, this study, which is based on the incorporation of transparent conductive IL, provides a new technical path for efficient multiclimate energy harvesting.