Abstract
Monte Carlo simulation of high-field transport in semiconductor nitrides GaN and InN is used to calculate the velocity field and the high-frequency behavior of differential mobility, spectral density of velocity fluctuations, and noise temperature. The spectra of hot-carrier differential mobility and velocity noise are found to exhibit a plateau in the low-frequency region, a peak at intermediate frequencies, and a 1/f2 decay at the highest frequencies. The comparison with standard A3B5 compounds shows that the characteristic frequencies associated with extreme and cutoff decay of the negative differential mobility, etc., are shifted to a higher-frequency range for the case of nitrides. This property is favorable for applications of nitrides in the terahertz frequency range.