Field Effect Optoelectronic Modulation of Quantum-Confined Carriers

in Black Phosphorus



William S. Whitney1, Michelle C. Sherrott2,3, Deep Jariwala2,3, Wei-Hsiang Lin2, Hans A. Bechtel4, George R. Rossman5, Harry A. Atwater2,3


1. Department of Physics, California Institute of Technology, Pasadena, CA 91125, USA
2. Thomas J. Watson Laboratory of Applied Physics, California Institute of Technology, Pasadena, CA 91125, USA
3. Resnick Sustainability Institute, California Institute of Technology, Pasadena, CA 91125, USA
4. Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
5. Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA 91125, USA

Abstract:

We report the infrared optical response of thin black phosphorus under field-effect modulation, and interpret the observed spectral shifts as a combination of an ambipolar Burstein-Moss (BM) bandgap shift due to band-filling and Pauli-blocking under gate control, together with a quantum confined Franz-Keldysh (QCFK) effect, which have been proposed theoretically to occur for BP flakes under electric field modulation. Modulation amplitudes as high as 15% are observed for 25 nm layers, suggesting the potential for use of black phosphorus as an active material in mid-infrared optoelectronic modulator applications.



last revised: 10-Aug-2010