To study the effects of degradation of phonon distribution on the high frequency response in nano structures

TL;DR

This paper investigates how non-equilibrium LO phonons affect the high-frequency response of GaN nanostructures, showing that phonon distribution degradation can improve cutoff frequency and response flatness.

Contribution

It introduces a model incorporating non-equilibrium LO phonons into the high-frequency analysis of GaN nanostructures, revealing their impact on device performance.

Findings

Degradation of phonon distribution increases 3-dB cutoff frequency.

Non-equilibrium phonons lead to flatter high-frequency response.

Including phonon effects improves understanding of GaN nanostructure performance.

Abstract

Under hot electron condition, the hot carriers phonon excited by ultra-short pulses in polar semiconductors initially loose energy rapidly by emitting longitudinal optic phonons via dominant Frolic coupling. Thus, energy supplied to the carriers by high electric fields goes into phonon generation. As the phonon life time is long enough, phonon distribution is disturbed and a non equilibrium population of LO phonons or hot phonons are produced, leading to their re-absorption by the carriers. In the present work the high frequency performance of GaN nanostructures is studied in the framework of heated drifted Fermi-Dirac distribution function incorporating the relevant scattering mechanisms and the influence of non-equilibrium LO phonons. It is observed that degradation of phonon distribution enhances significantly 3-dB cut off frequency thereby makes the high frequency response flatter reflecting that high frequency response is better if effects of non-equilibrium phonon distributions are included in the calculations.