Spatial confinement of carriers and tunable band structures in InAs/InP-core–shell nanowires

By means of first-principles calculations, we investigate the structural and electronic properties in a series of InAs/InP-core–shell nanowires with different sizes and compositions. Analysis of the subband charge density distributions reveals that both electrons and holes are spatially localized at the InAs-region of the core–shell nanowires, in consistent with a type-I band alignment. The size and composition effects on the confinement energies of electron carriers and the band gaps in the core–shell nanowires are investigated detailedly. These results provide an important guidance for the fabrication and applications of the core–shell nanowires.