1 research outputs found
Multiband theory of quantum-dot quantum wells: Dark excitons, bright excitons, and charge separation in heteronanostructures
Electron, hole, and exciton states of multishell CdS/HgS/CdS quantum-dot
quantum well nanocrystals are determined by use of a multiband theory that
includes valence-band mixing, modeled with a 6-band Luttinger-Kohn Hamiltonian,
and nonparabolicity of the conduction band. The multiband theory correctly
describes the recently observed dark-exciton ground state and the lowest,
optically active, bright-exciton states. Charge separation in pair states is
identified. Previous single-band theories could not describe these states or
account for charge separation.Comment: 10 pages of ReVTex, 6 ps figures, submitted to Phys. Rev.