Effect of metal nanoparticles' contact angle on absorption of light in organic solar cell active layer

Abstract

The enhancement in optical absorption efficiency in solar cells due to incorporation of metal nano-particles (MNPs) may depend on their properties including their contact angles. By appropriately choosing the materials for MNPs and layer on which they are to be deposited, the contact angle may be tuned to maximise optical absorption resulting in higher power conversion efficiency solar cells. In this work, we show by simulation studies that the contact angle of the MNPs with the surface on which they are deposited affects the optical absorption enhancement in an organic solar cell. For poly 3-hexythiophene: phenyl-C61-butyric acid methyl ester blend as the solar cell active layer, simulation studies for incident white light for constant projection area of MNP show that a 0° contact angle gives the highest enhancement in optical absorption. While the enhancement in absorption is observed to be higher for smaller wavelengths for smaller contact angles, the larger contact angle MNPs seems to help absorption in longer wavelengths.