Phonon Mean Free Path in Silicon Between 77 and 250°K

Abstract

Measurement of transmitted phonon drag across 10 ohm cm $p$-type silicon indicates a phonon mean free path of the relevant thermal phonons which varies from about 80 \ensuremath{\mu} at 77\ifmmode^\circ\else\textdegree\fi{}K to 12 \ensuremath{\mu} at 250\ifmmode^\circ\else\textdegree\fi{}K. The values depend on the method of evaluation. A simplified analysis suggests that below 150\ifmmode^\circ\else\textdegree\fi{}K the longitudinal acoustic branch of the phonon spectrum is dominant.