Plasmonic Materials for Broadband Solar Harvesting

Is it possible to design a dedicated nanostructure on which all surface features contribute entirely to energy harvesting within a solar cell? This is an  important challenge in the light that the effi ciency of the solar cell technology utilized has a direct impact on the required land use and also on reaching grid  parity . Here, a unique approach is used and an analytically derived optimum  solution to the problem is presented: a nanoscale metal topography , capable  of signifi cantly improving the effi ciency of solid state solar cells via excitation of surface plasmon polaritons (SPPs). The presented structure is designed to achieve broadband excitation of SPPs through the highest possible density  of desired k -vectors at the interface. This leads to high weighted absorption  enhancements ( > 130%) and unprecedented improvements ( > 30%) of solar  cell external quantum effi ciencies over the entire harvestable range.