We discuss the rules for designing nanostructured plasmonic backcontact of thin-film
crystalline silicon solar cells using two-dimensional finite-difference time-domain (2DFDTD)
method. A novel efficient quasi-periodic plasmonic nanograting is designed. Numerical
calculations demonstrate that broadband and polarization-insensitive absorption
enhancement is achieved by the proposed structure which is based on a supercell geometry
containing N subcells in each of which there is one Ag nanowire deposited on the
backcontact of the solar cell. The proposed structure offers the possibility of controlling
the number and location of photonic and plasmonic modes and outperforms the periodic
plasmonic nanogratings which only utilize plasmonic resonances. We start by tuning the
plasmonic mode of one subcell and then construct the supercell based on the final design
of the subcell. Our findings show that with a proper choice of key parameters of
the nanograting, several photonic and plasmonic modes can be excited across the entire
spectral region where crystalline silicon (c-Si) is absorbing. The absorption enhancement
is significant, particularly in the long wavelength region where c-Si is weakly absorbing.We discuss the rules for designing nanostructured plasmonic backcontact of thin-film
crystalline silicon solar cells using two-dimensional finite-difference time-domain (2DFDTD)
method. A novel efficient quasi-periodic plasmonic nanograting is designed. Numerical
calculations demonstrate that broadband and polarization-insensitive absorption
enhancement is achieved by the proposed structure which is based on a supercell geometry
containing N subcells in each of which there is one Ag nanowire deposited on the
backcontact of the solar cell. The proposed structure offers the possibility of controlling
the number and location of photonic and plasmonic modes and outperforms the periodic
plasmonic nanogratings which only utilize plasmonic resonances. We start by tuning the
plasmon