Nucleation Mechanism and Nanostructures Total Energy Calculation in CdTe-ZnTe-HgTe Material System

Аннотация

The continuum elasticity model is applied to investigate quantitatively the growth features and nucleation mechanism of quantum dots, nanopits, and joint QD-nanopits structures in CdZnHgTe quasyternary material system. We have shown that for the CdZnHgTe solid solution deposited on the CdTe substrate, the sign of the critical energy and volume of island is changed at the critical strain of ɛ^* = 0.006 and ɛ^* = 0.009 (ɛ = Δa/a), It is assumed that the mechanism of the nucleation is changed from the growth of quantum dots to the nucleation of nanopits at ɛ = ɛ^*. Obviously, at the small mismatch (ɛ < ɛ^*) the bulk nucleation mechanism dominates. However, at ɛ > ɛ^*, when the energy barrier becomes negative and a large mismatch provides a low-barrier path for the formation of dislocations, the nucleation of pits becomes preferable energetically.