Two step sintering process and metal grid design optimization for highly efficient ITO free organic photovoltaics

Abstract

The need for inexpensive alternative to indium doped tin oxide (ITO) transparent electrodes is imminent for cost-efficient solution processed optoelectronic applications. ITO-free transparent electrodes can be based on inkjet-printed Silver (Ag) nanoparticles grids embedded into PEDOT:PSS buffer layers. We present an in-depth investigation of the morphological evolution of the inkjet printed Ag nanopartricle sintering process combined with an ultimate control of the printed grid design requirements for efficient ITO-free organic photovoltaics (OPVs). We report on glass/ITO-free P3HT:PC60BM and Si-PCPDTBT:PC70BM based OPVs with power conversion efficiency of 2.8% and 4.9% respectively. These devices exhibited minimal losses when compared to reference ITO-based OPVs. © 2013 Elsevier B.V.