Possible deviations from AM1.5 illumination in coherent light simulations on plasmonic nanostructures in Perovskite solar cells

Abstract

The use of plasmonic nanostructures for light management in solar cells has been explored for conventional materials and is currently topic of interest for the perovskite solar cell. Often these studies make use of finite difference time domain (FDTD) simulations in which high intensity coherent light is used, which simultaneously generates multiple plasmon excitations in the plasmonic nanostructures in agreement with the quantum mechanical view . However, because of the relatively small photon flux of real sun light, in the classical view only one plasmon excitation can be generated at a time in real plasmonic nanostructured devices. In this work we demonstrate that the use of high intensity coherent light in simulations causes significant optical absorption variations due to surface plasmon polariton (SPP) interference, depending on incident light phase difference between neighboring plasmonic nanostructures. Because this is not possible under real sun light conditions in the classical view, this could constrain such FDTD simulations. The question therefore arises if a quantum mechanical view is more appropriate. In this case study the plasmonic nanostructures are embedded in Perovskite, which has a strong optical absorption from silver surface plasmon polaritons and is therefore sensitive to SPP interference. This study raises the question whether to mimic real sun light, SPPs should be separately generated at each individual plasmonic nanostructure, or that the quantum mechanical view leads to a better agreement with the experimental solar cell.