Ultrafast charge transfer from CdSe nanoparticles to methylviologen and single-walled carbon nanotubes and its effect on hybrid bulk heterojunction photovoltaic devices

CdSe nanoparticles combined with electron accepting materials, specifically methyl viologen (MV²⁺) and single walled carbon nanotubes (SWCNT), have been investigated. By using transient absorption spectroscopic measurements, ultrafast electron transfer has been shown to occur between the nanoparticles and the accepting materials. These composites were then mixed with poly(3-hexylthopene) to create hybrid bulk-heterojunction photovoltaic devices. It has been found that for matched concentrations (by weight), the composite materials show increased photocurrent when compared with CdSe nanoparticles.