Texture design of electrodes for efficiency enhancement of organic solar cells

Abstract

We report a simple solution-based approach to form ordered patterns of an indium tin oxide (ITO) electrode and underlying reasons for the improvement in power conversion efficiency (PCE) of organic solar cells (OSCs) built on the nanostructured ITO electrode. The patterning of ITO was achieved by using nanospheres as the template to erode ITO by wet chemical etching. Using a textured ITO anode for poly(3-hexylthiophene) (P3HT):[6,6]-phenyl C61-butyric acid methylester (PCBM) (P3HT:PCBM) OSCs enhanced PCE by 15% with respect to the non-patterned ITO anode. The improvement is mostly attributed to the morphological and interfacial changes stemming from the textured ITO electrode as well as enhanced light absorption due to the optimal morphology and refractive index change of patterned ITO. With its simplicity and time-saving, this method of fabricating a unique pattern of ITO electrodes can be widely applicable to a variety of large-area thin film solar cells.