High Frequency ac Transport of Two Dimensional Hot Electrons in GaN Quantum Wells

摘要

Small-signal ac transport of degenerate two dimensional hot electrons moving two dimensionally in a GaN quantum well is studied in the frame work of heated drifted Fermi - Dirac distribution function. The electron energy loss via polar optic phonon and the momentum loss through interactions with polar optic phonons, deformation potential acoustic phonons and background-ionized impurities are incorporated in the calculations. The ac mobility is found to remain fairly constant up to about 100 GHz beyond which it falls with increasing frequency of the applied field. The ac mobility is shown here to decrease with increasing channel width and to increase with increasing carrier concentration. The phase angle remains insignificant up to 10 GHz beyond which it increases with the rise of frequency of the applied field and is found higher at lower temperature. The 3dB frequency, where the ac mobility drops to 0.707 of its low frequency value is found to decrease initially and then rise with increasing carrier concentration and it is found higher at higher lattice temperature and at higher dc biasing field.