Theoretical Investigation to Analyze the Effect of Core Size of InAs/GaAs Core-Shell Nanostructure

Core-shell quantum dots (CSQD), are an appealing class of nanostructured semiconductor materials, recognised for their exceptional electronic and optical properties. They consist of a core material enclosed by a surrounding shell, hence earning them the name ‘core-shell’ quantum dots. An interesting property of CSQDs is the self-induced strain produced due to the difference in bandgap and lattice parameters of the respective materials, which is in turn related to the size of the core or shell layer. In our work, we have opted for III-V materials, InAs core coated with a GaAs shell layer to replicate a CSQD nanostructure, to theoretically study the effect of varying the InAs core size on the internal strain produced in the nanostructure. Variation in the InAs core layer size from 0.3–9 nm was seen to have an effect on the hydrostatic strain produced at the junction of the nanostructure, which led to an alteration in the band edge position of both the internal InAs core and the enclosing GaAs shell. This alteration in the position of band edges has a direct effect on the band gap of the respective nanomaterial, which in turn is a determining factor in tailoring or understanding the electrical and optical properties of these nanostructures.