Black Phosphorus Mid-Infrared Photodetector with Circular Au/Pd Antennas

Black phosphorus has been considered as one of the most capable two-dimensional materials for use in optoelectronic nanodevices due to its intrinsic layered nature structure, high mobility of carrier, and tunable bandgap. But its low light absorption prevents its use in high-efficiency photodetectors. In this study, the circular Au/Pd antenna-assisted black phosphorus mid-infrared photodetector which significantly improves the detection performance in comparison with BP photodetectors without antenna has been proposed. By integrating a circular Au/Pd antenna on the BP surface, the light-BP interaction was significantly increased. The simulation results demonstrate that metallic antenna structures improve both light absorption and photocarrier collection in BP phosphorus detectors. The numerical result shows that the photocurrent of the mid-infrared antenna-assisted BP detector was 5 times larger than that of BP photodetector without antennas