Abstract
he time and frequency behavior of hot-carrier velocity fluctuations in bulk semiconductors subjected to strong periodic electric fields is analyzed by using two complementary approaches based on the correlation function and the finite Fourier transform. Monte Carlo calculations performed for GaAs, InP, and InN show that semiconductor materials with a high value of the threshold field for the Gunn effect are characterized by a high value of the signal-to-noise ratio under high-order harmonics generation and, hence, they are promising materials for microwave generation in the terahertz frequency range by high-order harmonic extraction.