Design of Biomimetic Leaf-type Hierarchical Nanostructure for Enhancing the Solar Energy Harvesting of Ultra-thin Perovskite Solar Cells
Abstract
Ultra-thin perovskite solar cells have the advantages of low cost, high efficiency and flexibility, and have significant potential applications. However, a severe optical loss is often observed in the ultra-thin perovskite solar cell due to the insufficient light absorption. In this study, inspired by the efficient light harvesting of hierarchical structure in leaf, a biomimetic leaf-type hierarchical nanostructure was introduced for designing highly efficient ultra-thin perovskite solar cells. In detail, three layers of hexagonal arrays of silica nanoparticles with different radius were used to construct the biomimetic leaf-type hierarchical structure. The biomimetic leaf-type hierarchical nanostructure was optimized by a finite-difference time-domain method combined with a particle swarm optimization algorithm to reduce the light reflection and increase the light absorption of the ultra-thin perovskite solar cells. The results indicated that the biomimetic leaf-type hierarchical nanostructure could enhance the light absorption of ultra-thin perovskite solar cells by maximum 39% at the long wavelength. The photocurrent of the perovskite solar cells with a biomimetic leaf-type hierarchical nanostructure was 8.4% higher than that of perovskite solar cells without a biomimetic leaf-type hierarchical nanostructure.