Post-fabrication annealing effects on the performance of polymer: Fullerene solar cells with ZnO nanoparticles

Abstract

In this study, poly(3-hexylthiophene):[6,6]-phenyl C61-butyric acid methylester (P3HT:PCBM) organic photovoltaic (OPV) devices, with ZnO nanoparticles buffer layer between the photoactive layer (P3HT:PCBM) and the cathode (Al top electrode), were fabricated. The active layer were annealed at 140 ^oC before depositing the Zno and top electrode. The objective of this study was to investigate the effects of the ZnO buffer layer and pre-/post-fabrication annealing on the general performance of these devices. The short-circuit current density(J_SC) and open-circuit voltage (V_OC) of the OPV devices were improved by the insertion of the ZnO layer and post-fabrication annealing. This can be attributed to, among other things, improved charge transport across the interface between the photoactive layer and the Al top electrode as a result of post-annealing induced modification of the interface morphology.

Keywords: Organic, Photovoltaic, Heterojunction, Carriers.