Effect of carbon nanotube-fullerene hybrid additive on P3HT:PCBM bulk-heterojunction organic photovoltaics

The use of carbon nanotube-fullerene hybrid additives to the standard P3HT:PCBM blend bulk-heterojunction organic photovoltaic device is presented. The effects of incorporating single-wall carbon nanotubes, functionalized with linked C60 molecules by amination on device characteristics are detailed. The concentration of the carbon nanotube-fullerene hybrid in the active layer blend was varied to ascertain their cumulative impact on device performance in terms of open circuit voltage, short circuit current, fill factor and efficiency. We found that decreasing the length of the carbon nanotubes to ∼60 nm through fluorination and subsequent thermal treatment was beneficial in terms of eliminating shorted devices allowing much improved diode formation. A trend of improving device performance as a function of concentration of the carbon nanotube-hybrids in a heterojunction of P3HT:PCBM was observed.

► Single-walled carbon nanotubes functionalized with fullerenes as a hybrid additive in organic photovoltaics.
► Shortened single-walled carbon nanotubes allow for better diode formation and reduce shorted devices.
► The addition of carbon nanotubes or fullerene hybrids do not readily improve organic photovoltaic device efficiency.
► We conclude that pure semiconducting carbon nanotubes are required as the base additive material.