Heterogeneous semiconductor nanowire array for sensitive broadband photodetector by crack photolithography-based micro-/nanofluidic platforms.

The in situ growth of nanowires (NWs) into nano-/microelectromechanical systems (NEMS/MEMS) by solution processing is attractive for its relative simplicity and economic value. We present innovative, versatile microfabrication that produces multiple, heterogeneous semiconductor NWs. A crack photolithography-based micro-/nanofluidic platform has been developed. This platform offers the in situ solution growth of NWs while enabling the control of quantity, dimensions, orientation, alignment, position, and material. The generation of grain boundary (GB)-rich CH 3 NH 3 PbI 3 NWs using the micro-/nanofluidic device is exemplary. High-quality single-crystal CH 3 NH 3 PbI 3 NWs were derived by injection of a CH 3 NH 3 PbI 3 solution. We produced a parallel NW array of CH 3 NH 3 PbI 3 NW for visible light detection and ZnO NW for ultraviolet detection, thereby demonstrating an unprecedented broadband composite photodetector. The micro-/nanofluidic fabrication platform enables the production of multiple, heterogeneous semiconductor NW arrays on one substrate, offering the potential to elicit synergistic performance and functional enhancements from various NWs.