Strategically constructed hybrid bulk-heterojunction for efficient flexible self-powered infrared photodetectors with a carbon electrode.

The construction of an admirable hybrid bulk-heterojunction (HBH) can benefit the performance of optoelectronic devices through efficient charge separation and transportation. However, the present HBH structure still suffers from complicated layer-by-layer ligand exchanges during device fabrication. In this work, we apply a liquid phase exchange strategy in mixed colloidal hybrids composed of quantum dots (QDs) and nanotetrapods (NTs) and construct low-cost flexible self-powered infrared photodetectors with a carbon electrode. The one-pot ligand exchange enables a concentrated hybrid solution for one-step formation of a HBH film that delivers a superior photodetection with enhanced responsivity (1154 mA W) and detectivity (9.91 × 10 Jones) at 808 nm, a state-of-the-art performance for flexible carbon based self-powered photodetectors. The superior optoelectronic performance is attributed to facilitated charge transfer and depressed charge nonradiative recombination due to the existence of hyperbranched NTs and admirable surfactant exchange on hybrids.