Comparison of phonon-plasmon interaction in selected nanoparticle doped bulk and monolayer piezoelectric semiconductors in the presence of combined dc-ac fields

Abstract

As semiconductor plasma medium experiences the spread of an acoustic wave, the wave reacts with several basic excitations. An example of such excitations is plasmon. In such a reaction in the presence of certain physical conditions, there is a lost or gain of energy in the acoustic wave. Monolayer materials have offered several distinctive material concepts and properties that differ dramatically from their bulk counterparts. This work analytically studied longitudinal phonon-plasmon interaction in bulk (CdS) and monolayer (MoS2) semiconductors doped with nanoparticle cluster using fields of combined direct current-alternating current (dc-ac) and fields of commensurate frequencies. The theoretical formulation made use of the hydrodynamic model of plasma and macroscopic model of piezoelectric media to derive an expression for the acoustic gain (  ).Variation of the acoustic gain with velocity ratio, behavior of the acoustic gain per unit length sv with frequency and variation of the acoustic gain with carrier density ( 0en ) were explored graphically and investigated. The results show that velocity ratio ( i.e. the ratio of electrons drift velocity to sound velocity) is greatest for this monolayer material whenever it is subjected to both combined dc-ac fields and fields of commensurate frequencies. This variation also increases with increasing levels of nanoparticle (NP) cluster. Therefore, NP doped monolayer piezoelectric semiconductors will be better candidates for the fabrication of high speed sensors and transducers