HIGH-FREQUENCY CONDUCTIVITY, CARRIER WAVES, AND ACOUSTIC AMPLIFICATION IN DRIFTED SEMICONDUCTOR PLASMAS.

Abstract : The temperature modulation of charge carriers in a semiconductor is analyzed for a plane wave propagating along a static electric field. The effect of temperature modulation on the rf conductivity is considered. A phenomenological description of energy relaxation, momentum relaxation and intercarrier collisions is used. The expression for conductivity is used to derive a dispersion relation for carrier waves in drifted semiconductor plasmas. Two new waves are introduced by relaxing the assumption of isothermal carrier transport. The theory is applied to a discussion of acoustic amplification in piezoelectric semiconductors. It is shown that the non-isothermal effects limit the maximum gain which can be achieved at high frequencies. (Author)