Hot-electron noise and energy relaxation in wurtzite ZnO

Hot-electron noise measurements at a 38.5 GHz frequency were used for extraction of hot-electron energy relaxation time in a ZnO/Mg 0.38 Zn 0.62 O/ZnO channel with a two-dimensional electron gas (2DEG). The relaxation time of ∼55 fs was obtained at a 2DEG density of ∼ 5.5 × 10 12 cm −2 . The ultrafast relaxation took place in the vicinity of LO-phonon- plasmon resonance. The results suggest that the power dissipation is enhanced by plasmons. The results are in good agreement with those reported for GaN and InGaAs 2DEG channels and doped ZnO films.