Grant: Strategic Projects - Group

Black phosphorus is a stable allotrope of phosphorus that exhibits a layered structure that can be exfoliated,like graphene, down to a single monolayer. This elemental 2D semiconductor offers several distinctivefeatures: remarkably high carrier mobilities, an anisotropic band structure, and a direct gap that efficientlyabsorbs light. In addition, BP offers two characteristics unmatched by any other 2D or bulk materials: a tunabledirect bandgap from the mid-infrared to the visible via the sample thickness and the ability to dynamically tunethe gap through an applied electric field. These characteristics present unique opportunities for thedevelopment of low-cost photodetectors with enhanced responsivities and operating frequencies in thetechnologically important infrared region of the spectrum. In close partnership with Excelitas, one of the mostimportant photodetector manufacturers in the world, we will develop a number of infrared photodetectorarchitectures based on BP. In particular, we will develop electric-field tunable BP photodetectors to extend theintrinsic spectral range of BP beyond 4 microns, we will enhance their sensitivity by using optical metasurfacesand finally we will develop low-cost large-area BP detectors using solution-based processing of BPnanoparticles. Black phosphorus detectors will have potential applications in telecommunications,spectroscopy, range finding and thermal imaging. Within the context of this Project, we will specificallybenchmark BP tunable detectors as potential trace gas sensors.