Black phosphorus photodetector integrated with Au nanoparticles

In this study, we propose a hybrid black phosphorus (BP)/Au nanoparticle (NP)-based photodetector, which greatly enhances the performance of photodetectors compared to BP-only photodetectors. By integrating Au NPs onto the BP surface, the light absorption was greatly enhanced owing to the localized surface plasmon resonance induced by the Au NPs, and the dark current of the photodetector was suppressed because the holes were withdrawn from the BP to the Au NPs due to the difference in the work function. After optimizing the density of the Au NPs, the responsivity of the BP/Au-NP photodetector reached 6000 and 500 A/W for 655 and 980 nm wavelengths, respectively, which are 60 and 500 times higher than those of BP photodetectors, respectively. The proposed hybrid photodetector, a two-dimensional (2D) semiconductor with noble metal NPs, opens up the possibility of realizing highly sensitive optoelectronic devices in the future.