Effect of Misfit and Threading Dislocations on Surface Energies of PbTe-PbSe Interfaces

TL;DR

This study investigates how misfit and threading dislocations influence the surface energies of PbTe-PbSe interfaces, revealing that dislocation structures significantly alter interfacial energy, with implications for material design.

Contribution

It provides a detailed quantification of the impact of dislocation types on surface energies of PbTe-PbSe interfaces using atomistic and multiscale simulations.

Findings

Direct bonding yields ~23% lower surface energy than coherent interfaces.

Heteroepitaxial interfaces can have nearly 50% lower surface energy.

Dislocation structures significantly affect interfacial energy.

Abstract

This work quantifies the effect of misfit and threading dislocations on the surface energies of PbTe-PbSe interfaces, with the defect structures of the interfaces being obtained from atomistic and multiscale simulations of their manufacturing processes. Simulation results show that direct bonding produces semi-coherent interfaces with two-dimensional misfit dislocation networks, while heteroepitaxial processes produce complex three-dimensional dislocation structures with both misfit and threading dislocations. Surface energies at these interfaces were determined by computing the interaction energies across these interfaces. Compared with coherent interfaces, directly bonded interfaces exhibit up to ~23% lower surface energy, while the surface energies of epitaxially grown interfaces can be nearly 50% lower. The results demonstrate the significant effects of dislocations on interfacial energy.