Dual-periodic-corrugation-induced broadband light absorption enhancement in organic solar cells

We demonstrate an efficient approach to realize broadband light trapping in organic solar cells (OSCs) by integrating two-dimensional dual periodic corrugations. The dual-periodic corrugations consist of two set different periodic gratings, and have the effect to excite the surface plasmon-polariton (SPP) resonance associated with the cathode/organic interface in broadband wavelength region by adjusting befitting periods of the microstructures. Experimental and numerical results demonstrate that light absorption in OSCs has been enhanced in broadband owing to the effect of SPP-induced field enhancement. The short-circuit photocurrent density is improved from 4.072 to 5.365 mA/cm(2), and a 31% enhancement of power conversion efficiency has been obtained compared to the conventional planar devices. (C) 2015 Elsevier B.V. All rights reserved.