Band-Edge Diagrams of Core-Shell Semiconductor Dots

We have calculated band-edge diagrams for spherical core shell nanocrystal quantum dots for all combinations of AlN, GaN, and InN, as well as all combinations of AlP, GaP, AlAs, GaAs, InP, In As, AlSb, GaSb, and LnSb, as a function of core radius, with the outer radius of the shell held fixed. We have calculated the Gamma- and the X-conduction band minima, the valence band maximum, and the effective masses using strain-dependent eight-band kp theory, with a linear continuum model for the strain. We have found all the band alignments that may occur, and identified all combinations where one material becomes metallic due to a negative gap. Structures which are suitable for biological applications have been identified. We provide a figure which allows easy calculation of the confinement energy using a single band model.