Solvation-Induced Morphology Effects on the Performance of Polymer-Based Photovoltaic Devices

Abstract

Polymer-based photovoltaic devices have been fabricated by blending the conjugated polymer, poly(2-methoxy-5-(2′-ethylhexyloxy)-1,4-phenylenevinylene) (MEH-PPV) with the buckminsterfullerene, C60. The photo-induced current and the open-circuit voltage show a strong dependence on the polymer processing conditions. It was found that the photovoltaic devices fabricated with tetrahydrofuran or chloroform (non-aromatic solvents) have smaller photocurrents under same reverse bias as well as higher open circuit voltages than the devices fabricated with xylene, dichlorobenzene, or chlorobenzene (aromatic solvents). The device performance dependence on the processing solvent is attributed to the different solvation-induced polymer morphology.