Projects per year
Layered two-dimensional materials have demonstrated novel optoelectronic properties and are well suited for integration in planar photonic circuits. Graphene, for example, has been utilized for wideband photodetection. However, because graphene lacks a bandgap, graphene photodetectors suffer from very high dark current. In contrast, layered black phosphorous, the latest addition to the family of two-dimensional materials, is ideal for photodetector applications due to its narrow but finite bandgap. Here, we demonstrate a gated multilayer black phosphorus photodetector integrated on a silicon photonic waveguide operating in the near-infrared telecom band. In a significant advantage over graphene devices, black phosphorus photodetectors can operate under bias with very low dark current and attain an intrinsic responsivity up to 135 mA W-1 and 657 mA W-1 in 11.5-nm- and 100-nm-thick devices, respectively, at room temperature. The photocurrent is dominated by the photovoltaic effect with a high response bandwidth exceeding 3 GHz.
Bibliographical noteFunding Information:
This work is supported by the Air Force Office of Scientific Research (award no. FA9550-14-1-0277) and the National Science Foundation (NSF, award no. ECCS-1351002). M.L. thanks X.H. Chen and G.J. Ye of University of Science and Technology of China for providing some of the black phosphorus samples at the initial stage of the project. Parts of this work were carried out in the University of Minnesota Nanofabrication Center, which receives partial support from the NSF through the National Nanotechnolgy Infrastructure Network (NNIN) programme, and the Characterization Facility, which is a member of the NSF-funded Materials Research Facilities Network via the Material Research Science and Engineering Center (MRSEC) programme.
How much support was provided by MRSEC?
Reporting period for MRSEC
- Period 1