Abstract. We analyzed the steady-state electron transport for bulk GaN in frame of two opposite approaches: the electron temperature approach that assumes a high-density electron gas and numerical single-particle Monte-Carlo method that assumes a low- density electron gas and does not take into account electron-electron (e-e) scattering. We have also presented an analytical solution of the Boltzmann transport equation based on diffusion approximation. The transport characteristics such as the drift velocity electric field,   E V d , and mean electron energy electric field,   E  , have been calculated at nitrogen and room temperatures in the wide range of applied electric fields from zero fields up to runaway ones (~100 kV/cm) for both approaches. Our calculations were performed for doped semiconductor with equal impurity and electron concentrations, 3 16 cm 10    n N i . The electron distribution functions in various ranges of applied fields have been also demonstrated. Within the range of heating applied fields 0– 300 V/cm, we found a strong difference between the transport characteristics obtained by means of the balance equations (electron temperature approach) and Monte-Carlo procedure. However, the Monte-Carlo calculations and diffusion approximation show a good agreement at 77 K. Within the range of moderate fields 1–10 kV/cm at 77 K, we established that the streaming effect can occur for low-density electron gas. In spite of significant dissimilarity of a streaming-like and a shifted Maxwellian distribution functions, the calculated values of   E V d and   E  show similar sub-linear behavior as the functions of the applied field E. In the high-field range 20–80 kV/cm, the streaming effect is broken down, and we observe practically linear behavior of both   E V d and   E  for both approaches. At higher fields, we point out the initiation of the runaway effect.

Keywords: Monte Carlo method, gallium nitride, electron transport.

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