Improvement of organic solar cell performance by multiple plasmonic excitations using mixed-silver nanoprisms

Three different silver nanoprisms (AgNPrs) were combined and used as light-trapping materials in organic solar cells (OSCs). These mixed AgNPrs (M-AgNPrs) increased the photocarrier generation in the OSCs due to the broadband absorption, which was attributed to mutual multiple plasmonic excitations covering the entire visible light region. The M-AgNPrs were incorporated into a poly(3,4-ethylenedioxythiophene): poly(styrenesulfonate) hole-transport layer in the OSCs. The UV–vis spectra, atomic force microscope images and current density versus voltage curves of the fabricated devices were recorded at different loading concentrations of the M-AgNPrs. Finite-difference time-domain simulation, impedance spectroscopy, and measurement of incident photon-to-current efficiency of the devices confirmed the effect of the multiple plasmonic excitations. The results suggest that, in an optimum condition, the efficiency of the OSCs loaded with M-AgNPrs was 7.9% higher than the reference OSC.