Anisotropy of the Γ-point effective mass and mobility in hexagonal InN

We determine the anisotropic electron effective mass and mobility parameters in wurtzite InN thin films with free electron concentration N from 1.8 × 10¹⁷ cm^-3 to 9.5 × 10¹⁸ cm^-3 using Infrared Magneto-optic Generalized Ellipsometry. The room-temperature measurements were carried out with magnetic fields up to 4.5 T. For the Γ-point we estimate m_⊥* = 0.047m ₀ and m_∥* = 0.039m₀ for polarization perpendicular and parallel to the c-axis, respectively. Scattering by impurities or ionized donors may explain the decrease of mobility for polarization parallel to the c-axis from 1600 cm²/(Vs) to 800 cm²/(Vs) with increase in N, where the perpendicular mobility is further decreased, likely caused by additional grain boundary scattering.