Plasmonic-Enhanced Photocurrent Generation of Organic Photovoltaics Induced by 1D Grating and 2D Crossed Grating Structures.

In this work, plasmonic-enhanced photocurrent generation in organic photovoltaic (OPV) devices is demonstrated. One-dimensional (1D) and two-dimensional (2D) crossed grating structures are created on the active-layer surface composed of a blend of poly(3-hexylthiophene-2,5-diyl) (P3HT) and [6,6]-phenyl C61 butyric acid methyl ester (PC61BM) via a nanoimprinting technique using a template of a Blu-ray disc recordable (BD-R) grating structure. After formation of aluminum back electrodes, the grating-coupled surface plasmon (GCSPR) and light scattering observed in the devices with grating structures provide a 12.3% and 11.0% enhancement of the photocurrent for the devices with 1D grating and 2D crossed grating structures, respectively. The OPV devices with the 2D crossed grating show a plasmonic-enhanced photocurrent under irradiation with light with all polarization directions, whereas those with the 1D grating provide plasmonic enhancement only under illumination with p-polarized light.