We have calculated electron mobilities in InN and its III-nitride alloys using a variational procedure and taking into account the standard scattering mechanisms of Coulomb scattering, alloy disorder, and optical and acoustic phonons. The effects of the nonparabolicity of the conduction band and resulting energy-dependent effective mass have also been included. Scattering from charged Coulombic centers and alloy disorder are the dominant scattering mechanisms that limit the mobilities in currently available materials. Phonons play a role only in relatively pure (n< 1018 cm-3) samples or at very high temperatures (T>400 K). In addition, our calculations are in good agreement with experimental Hall mobilities obtained through controlled doping studies performed on InN, InGaN, and InAlN by high energy irradiation.
Bibliographical noteFunding Information:
This work was supported in part by the Director, Office of Science, Office of Basic Energy Sciences, Division of Materials Sciences and Engineering, of the U.S. Department of Energy under Contract No. DE-AC02-05CH11231. R.E.J. acknowledges support from a National Defense Science and Engineering Graduate fellowship. The authors would like to thank Bill Schaff for providing the samples that were irradiated.