Plasmon-enhanced parabolic nanostructures for broadband absorption in ultra-thin crystalline Si solar cells.

Sub-wavelength plasmonic light trapping nanostructures are promising candidates for achieving enhanced broadband absorption in ultra-thin silicon (Si) solar cells. In this work, we use finite-difference time-domain (FDTD) simulations to demonstrate the light harvesting properties of periodic and parabola shaped Si nanostructures, decorated with metallic gold (Au) nanoparticles (NPs). The active medium of absorption is a 2 μm thick crystalline-silicon (c-Si), on top of which the parabolic nanotextures couple incident sunlight into guided modes.

Coscinodiscus diatom inspired bi-layered photonic structures with near-perfect absorptance Part II: hexagonal vs. square lattice-based structures.

In this follow up of our previous work on bio-inspired photonics [Opt. Express28, 25007 (2020)10.1364/OE.

Coscinodiscus diatom inspired bi-layered photonic structures with near-perfect absorptance accompanied by tunable absorption characteristics.

Inspired by the morphology of Coscinodiscus species diatom, bi-layered photonic structures comprised of dielectric-filled nano-holes of varying diameters have been designed and analyzed to enhance and tune absorption characteristics of GaAs-based thin-film photonic devices. Finite difference time domain-based numerical analysis and effective medium approximation based theoretical calculations show that by adjusting diameter and areal density of the nano-holes of the two layers, the peak absorption wavelength can be tuned over a wide spectral range, while attaining a maximum peak-absorptance value of about 97% and a maximum absorption bandwidth of ∼ 190 nm. The maximum enhancement factor of the bi-layered structure is about 11% higher than the value obtained for its equivalent single-layered counterpart over the near-ultraviolet to visible regime of the spectra.