Emission and absorption of phonons in silicon

We examine in detail the rates of phonon emission and absorption in silicon at several values for the applied electric field. The effect of the field on the electron distribution is obtained from full-band Monte Carlo simulation for bulk silicon. The electron distributions are used to numerically compute the phonon rates and learn about their behavior at high fields. The concept of electron temperature is used to understand the relationship between field and heat emission, and it is found that longitudinal acoustic (LA) phonon emission increases at high fields. Optical absorption is found to be small, while optical phonon emission stays constant across a wide range of electron temperatures. Strong emission of LA phonons at high field can be used to enable heat-conscious design of future silicon devices.