Fast two-phonon relaxation process between the Landau levels of graphene on different polar substrates
1 Tianjin Key Laboratory of Low Dimensional Materials Physics and Preparing Technology, Department of Physics, Tianjin University - Tianjin 300072, China
2 Suzhou Institute of Nano-tech and Nano-bionics, CAS - Suzhou 215125, China
Received: 28 July 2014
Accepted: 14 October 2014
Within the frame of Huang-Rhys's lattice relaxation model, we theoretically investigate the carrier relaxation mediated by two-phonon processes, which consists in polar surface optical phonon and longitudinal acoustic phonon emission between the Landau levels of graphene on different polar substrates. This two-phonon relaxation process is very fast within the picosecond scale and may seriously hinder the carrier multiplication based on effective Auger processes. Moreover, the polarizability of the polar substrate plays an important role in determining the relaxation time. These results could be helpful in designing graphene-based photoelectric and photodetector devices.
PACS: 63.22.Rc – Phonons in graphene / 78.67.Wj – Optical properties of graphene / 68.49.Jk – Electron scattering from surfaces
© EPLA, 2014