Effect of printing parameters and annealing on organic photovoltaics performance

In this paper, ink-jet printing was used to deposit poly(3-hexylthiophene):phenyl-C61-butyric acid methyl ester blend as active layer and a comparison study of three printing methods [multiarray (MA), single layer array, and multilayer array] was performed. For organic photovoltaics (OPVs) fabricated using MA or multilayer arrays, the efficiency was less than 1% independent of printing parameters. When single layer print pattern was used, the device performance improved significantly and an efficiency of 1.29% was obtained, indicating that the thin films fabricated using a single layer are more suitable for OPVs than films obtained by overlapping of multiple layers. The influence of annealing parameters on electrical and optical thin film properties was also investigated. The study found that the optimum annealing condition for the printed OPVs is solvent annealing at 60 °C, yielding an efficiency of 1.99%.