A Raman scattering-based method to probe the carrier drift velocity in semiconductors: Application to gallium nitride

Abstract

A single expression relating the carrier drift velocity in semiconductors under an electric field to Raman scattering data is derived resorting to a full nonequilibrium picture for electrons and holes. It allows one to probe with high optical precision both the ultrafast transient as well as the steady state carriers' drift velocity in semiconductor systems. This is achieved by simply modifying the experimental geometry, thus changing the angle between the transferred wave vector Q and the applied electric field E, and measuring the frequency shift promoted by the presence of the field to be observed in the single-particle and plasmon scattering spectra. An application to zinc-blende gallium nitride is presented to highlight the power of the method.

Nonlinear charge transport in III-N semiconductors: Mobility, diffusion, and a generalized Einstein relation

“…24͒ and v e in measurements of electroabsorption 25 or with better definition in measurements of Raman scattering by plasmon modes. 26 …”

Nonlinear transport properties of doped III-N and GaAs polar semiconductors: A comparison

“…Recently an alternative, and apparently more precise, experimental procedure resorting also to optical measurements has been suggested-Raman scattering of carriers in electric fieldwhich can also allow for measurements in the transient regime ͑femtosecond scale͒. 26…”

Nonlinear charge transport in highly polar semiconductors: GaN, AlN, InN and GaAs

“…[25]), which is somewhat imprecise. An alternative, and apparently more precise, experiment using optical measurements has been suggested -Raman scattering of carriers under an electric field -that can also allow for measurements in the transient regime (femtosecond scale) [147].…”