Photon management by metallic nanodiscs in thin film solar cells

We investigate the absorption enhancement by metallic nanodiscs in thin-film amorphous silicon solar cells. The effect is quantitatively evaluated by rigorously solving Maxwell's equations. We show that 50% more photons can be absorbed using geometries accessible for current nanofabrication technologies. Moreover, the thinner the solar cell, the larger the absorption enhancement. Detailed investigations prove that the enhancement can be related to the excitation of localized plasmon polaritons. The simultaneous enhancement in both the near-field amplitude and the scattering cross section at resonance as the leading physical mechanism is discussed in detail.