Photodiode arrays fabricated from semiconducting polymers offer unique opportunities. Large area, flexible image sensors can now be fabricated for use in space technology, in military applications and in business and consumer electronics where single crystal semiconductors are impractical. The photosensitivity of semiconducting polymers can be significantly enhanced by blending with conjugated polymers or organic molecules with different electron affinities. In such polymer blends, donor/acceptor hetero-junctions form at the interface of the two co-mingled species. With control of the processing paramenters, this can be made to occur in bicontinuous networks on the nanometer length scale. Charge transfer occurs after photoexcitation; the photoinduced electrons transfer to the acceptor while the photoinduced holes remain on the donor. High photosensitivity photodiodes with conjugated polymers and polymer blends have been demonstrated, and enable a novel approach to the fabrication of large area, high sensitivity image sensors at low cost. The proposed research has the goal of establishing the viability of polymer photosensors with ultrafast response (>10GHz), and large dynamic range, on flexible substrates suitable for complicated wavefront detection. We will focus on identifying materials appropriate for the spectral ranges of interest, on demonstrating ultrafast response (>10GHz) and on optimizing device parameters.
Keywords: Photodetector, Flexible, Ultrafast Response, Photodiode
