Antireflective Indium-Tin-Oxide Nanobranches for Efficient Organic Solar cells

Abstract

Indium tin oxide (ITO) nanobranched structures with low reflectance have been designed for application to organic solar cells. The ITO nanobranches are deposited on the front surface of glass without damages to organic active layer by using an electron beam deposition. Through a finite-difference time-domain, we find that the field intensity in the glass region is enhanced with ITO nanobranches. Consequently, the number of incident photons induces strong absorption within the PTB7-PC70BM active layer, leading to the enhanced short circuit current density (J(sc)). Compared with a flat device (power conversion efficiency (PCE) = 6.53%, J(sc) = 13.3 mA/cm(2)), improved PCE of 7.09% is achieved in an antireflection coating, which is mainly due to the increased J(sc) of 14.2 mA/cm(2). (C) 2016 AIP Publishing LLC.