Photo-induced charge recombination kinetics in low bandgap PCPDTBT polymer: CdSe quantum dot bulk heterojunction solar cells

The interfacial charge transfer recombination processes under working conditions that limit the device performance in polymer: CdSe quantum dot bulk heterojunction hybrid solar cells have been measured. The recombination lifetimes for electrons and holes in the device show an exponential dependence in a similar way to that observed for other molecular based solar cells such as bulk heterojunction organic solar cells (OSC) and dye sensitized solar cells (DSSC). The implications of this unprecedented observation on the design of novel devices are discussed as well as the relationship between the charge accumulation in these devices under operation and the device open-circuit voltage.