Improved P3HT:PCBM photovoltaic cells with two-fold stabilized PbS nanoparticles

Lead sulfide nanoparticles have been synthesized by a simple, low-temperature method, using thiophenol and decanethiol as stabilizing agents. Transmission electron microscopy characterization shows nanocrystals with an average size of 4.5 nm. Optical absorption spectroscopy suggests that strong quantum confinement of charge carriers has been achieved. The nanoparticles have been easily incorporated into a poly(3-hexylthiophene):phenyl-C61-butyric acid methyl ester in chlorobenzene solution. A photovoltaic cell has been fabricated using this mixture as active layer and compared to a reference cell without nanoparticles. Electrical measurements show a significant improvement of the electrical characteristics of the photovoltaic cell based on the hybrid material.