Molecular heterojunction photovoltaic cells: Photocarrier behavior and nanostructures

We show that the photocarrier behavior in molecular heterojunction (HJ) photovoltaic cells is significantly influenced by the structure of the molecular HJ by examining the voltage dependencies of the photocurrent in planar, mixed, and planar-mixed HJ cells. We further demonstrate the synthesis of vertically aligned, crystalline molecular nanorods using the oblique angle deposition method. Based on these nanorods, photovoltaic cells with efficiency doubling that of bilayer devices are also demonstrated.