Hot phonons in Si-doped GaN

Microwave noise and electron transport are studied in silicon-doped GaN channels grown by molecular beam epitaxy and subjected to a high electric field. The drift velocity of $2.8×107cm∕s$ is reached at $290kV∕cm$ for $n∼1×1018cm−3$ channel. No negative differential resistance is observed. The noise temperature exceeds $∼5000K$ at $∼110kV∕cm$ for $n∼3×1017cm−3$ channel. The hot-phonon effect on power dissipation in GaN:Si is 3–4 times weaker as compared with the effect in an undoped $AlGaN∕GaN$ two-dimensional channel. Monte Carlo simulation shows a weak effect of hot phonons on hot-electron energy distribution.