Figure 4. k·p calculations of the CdSe/CdS band structure.

(a) Plot of the overall band structure along the long axis of the RIR sample III. The potential wells are strongly asymmetric, with a valence band maximum and conduction band minimum at opposite sides of the core CdSe nanorod. The indirect transition also has an energy below the bulk CdSe bandgap. (b) Corresponding two-dimensional plots. (c) Electron (left) and hole (right) wavefunctions are well separated, confirming the indirect exciton ground state. (d) The electron–hole overlap for RIRs of increasing size rapidly decreases when piezoelectricity is taken into account (solid line), while it otherwise remains above 80% (dashed line). The core has an aspect ratio of 1:3 and the shell is twice as large.