Atomistic tight-binding computations in the new class of CdSe/AlP II-VI core/III-V shell nanocrystals

摘要

Using the atomistic tight-binding theory in conjunction with a configuration interaction description, I investigate the new class of CdSe/AlP II-VI core/III-V shell nanocrystals. In an effort to theoretically analyze the atomistic behaviors, I calculate single-particle spectra, atomistic character, optical band gaps, ground-state wave function overlaps, ground-state oscillation strengths, ground-state Coulomb energies, ground-state exchange energies, Stokes shift and fine structure splitting under different numbers of the growth shell monolayers (MLs). I highlight that CdSe/AlP II-VI core/III-V shell nanocrystals have strong thickness dependence on the structural and optical properties. The reduction of the optical band gaps is recognized with the increasing coated shell thickness because of quantum confinement. The improvement of wave function overlaps, oscillation strengths, Stokes shift, and fine structure splitting is demonstrated at the growth shell thickness of 1.0 ML. This atomistic prediction will contribute to the understanding of natural properties in the new class of colloidal CdSe/AlP II-VI core/III-V shell nanocrystals and will deliver some significant guidelines for further experimental investigations.