Panchromatic cross-conjugated π-bridge NIR dyes for DSCs.

Four organic sensitizers incorporating a cross-conjugated cyclopenta[2,1-b:3,4-b']dithiophene (CPDT) π-bridge have been synthesized. As a result of molecular engineering, broad high energy bands and red shifted absorption maxima and onset is observed relative to a benchmark analogue (C218) using a non-cross-conjugated CPDT π-bridge. The use of a cross-conjugated bridge allows a new strategy for tuning dye energetics and introduction of increased absorption uniformity by adding additional high-energy absorption bands.

Temperature-Dependent Detectivity of Near-Infrared Organic Bulk Heterojunction Photodiodes.

Bulk heterojunction photodiodes are fabricated using a new donor-acceptor polymer with a near-infrared absorption edge at 1.2 μm, achieving a detectivity up to 10 Jones at a wavelength of 1 μm and an excellent linear dynamic range of 86 dB. The photodiode detectivity is maximized by operating at zero bias to suppress dark current, while a thin 175 nm active layer is used to facilitate charge collection without reverse bias.