Optical and electrical properties of 3D patterned hydrophobic thin film for integrated energy harvester

Abstract Solar cell is currently the most widely used micro-energy harvesting device in outdoor unattended system field due to high conversion efficiency. However, the photoelectric conversion efficiency of solar cells is easily affected by surface reflection, dust pollution and weather conditions. Meanwhile, the reported researches only alleviated the influence of some of these factors. Here, an integrated energy harvester with a multifunctional 3D patterned hydrophobic thin film was designed to maintain and improve the working performance of solar cells. In which, the patterned film serves as both a self-cleaning and an anti-reflection layer to enhance the performance of solar cell, also, it can accumulate charges based on triboelectric mechanism when raindrops hit its surface. Compared with the tempered glass coated solar cell, the power conversion efficiency of the patterned film coated solar cell can be increased by 1.45%. In addition, by reducing the van der Waals force between the dust and the film, enhancing the hydrophobicity of the surface and achieving electrostatic dust removal based on the friction mechanism, multi-effect self-cleaning effect can be achieved. Furthermore, while achieving the electrostatic dust removal, the patterned film can also collect raindrop energy as a beneficial supplement to solar cells in rainy days. Therefore, the introduction of multifunctional 3D patterned film with excellent optical and electrical properties provides a simple and low-cost technical strategy and a stronger guarantee for the high efficiency and wide application of solar cells.