Intervalley-Scattering Induced Electron-Phonon Energy Relaxation in Many-Valley Semiconductors at Low Temperatures

TL;DR

This paper investigates how elastic intervalley scattering affects electron-phonon energy transfer in many-valley semiconductors at very low temperatures, providing a theoretical model validated by experiments on doped silicon.

Contribution

It introduces a general expression for electron-phonon energy flow considering dominant elastic intervalley scattering, supported by experimental validation.

Findings

Theoretical expression matches experimental data

Elastic intervalley scattering significantly influences energy relaxation

Electron heating experiments confirm the model's accuracy

Abstract

We report on the effect of elastic intervalley scattering on the energy transport between electrons and phonons in many-valley semiconductors. We derive a general expression for the electron-phonon energy flow rate at the limit where elastic intervalley scattering dominates over diffusion. Electron heating experiments on heavily doped n-type Si samples with electron concentration in the range $3.5-16.0\times 10^{25}$ m$^{-3}$ are performed at sub-1 K temperatures. We find a good agreement between the theory and the experiment.