Photo-excited charge carriers suppress sub-terahertz phonon mode in silicon at room temperature.

ABSTRACT: There is a growing interest in the mode-by-mode understanding of electron and phonon transport for improving energy conversion technologies, such as thermoelectrics and photovoltaics. Whereas remarkable progress has been made in probing phonon-phonon interactions, it has been a challenge to directly measure electron-phonon interactions at the single-mode level, especially their effect on phonon transport above cryogenic temperatures. Here we use three-pulse photoacoustic spectroscopy to investigate the damping of a single sub-terahertz coherent phonon mode by free charge carriers in silicon at room temperature. Building on conventional pump-probe photoacoustic spectroscopy, we introduce an additional laser pulse to optically generate charge carriers, and carefully design temporal sequence

SUBMITTER: Liao B 

PROVIDER: S-EPMC5064017 | biostudies-literature | 2016 Oct

REPOSITORIES: biostudies-literature