The carrier contribution to the elastic constants in quantum wire superlattices of compound semiconductors with graded structures: Simplified theory and a suggestion for experimental determination

摘要

In this paper, an attempt is made to study the carrier contribution to the elastic constants in III-V, II-VI, PbTe/PbSnTe, strained layer and HgTe/CdTe quantum wire superlattices (QWSLs) with graded structures and compare the same with that of the constituent materials by formulating the respective dispersion laws. It is found, taking GaAs/Ga1-xAlxAs, CdS/CdTe, PbTe/PbSnTe, InAs/GaSb, and HgTe/CdTe QWSLs as examples that the second and third order elastic constants increase with increasing electron concentration and inverse film thickness respectively in different oscillatory manners and the nature of oscillation is totally band structure dependent. The width of the finite interface affects significantly the numerical values of the second and third order elastic constants for all the aforementioned QWSLs. We have suggested an experimental method of determining the electronic contribution to the elastic constants in materials having arbitrary dispersion laws. Besides, the well-known expressions for the bulk specimens of wide gap materials have also been obtained as a special case of our generalized analysis under certain limiting conditions.