High-detectivity inverted near-infrared polymer photodetectors using cross-linkable conjugated polyfluorene as an electron extraction layer

We report an alcohol- and water-soluble and cross-linkable conjugated polymer used as an electron extraction layer (EEL) in near-infrared (NIR) polymer photodetectors (PDs) with an inverted device structure. Effectively suppressed dark current with significantly improved photocurrent result in enhanced detectivities for the inverted NIR polymer PDs incorporating the polymer EEL. Operating at room temperature, the inverted polymer PDs possess a spectral response from 350 nm to 1100 nm, responsivity of 116 mA W−1 and detectivity of 1.02 × 1013 cm Hz1/2 W−1. Our results provide a promising pathway for fabricating high-sensitivity inverted NIR polymer PDs.