Synergistic Charge Generation and Collection Enabled by Incorporation of Crystalline Polymer for Ultrafast-Response...

Dual-band photodetectors (PDs) capable of selectively responding to both visible and near-infrared (NIR) light are essential for applications in optical communication, medical diagnostics, and artificial vision systems. In this work, we report a high-performance visible/NIR dual-band PD based on a vertically stacked perovskite/organic hybrid structure. To overcome the challenges of high operating voltage and slow response, often stemming from high exciton binding energy and limited charge transport in organic semiconductors, we introduce a synergistic strategy that enhances both charge generation and collection. This is achieved by incorporating a gTAP donor polymer into a binary organic bulk heterojunction (BHJ). The presence of gTAP significantly promotes exciton dissociation and charge extraction within the active layer due to its high crystallinity, planar structure, and high dipole moment. As a result, the optimized device delivers excellent dual-band performance, with peak responsivities of 345 mA (at 0.1 V, visible mode) and 325 mA (at -0.5 V, NIR mode), along with fast rise/decay times of 2.78/1.78 and 7.09/2.82 μs, respectively. This approach demonstrates a promising route for the design of low-power, fast-switchable, and multispectral photodetectors, advancing their integration into next-generation imaging and optical communication system.