Excitons in type-II quantum dots: Finite offsets

Quantum size effects for an exciton attached to a spherical quantum dot are calculated by a variational approach. The band lineups are assumed to be type II with finite offsets ${\mathit{V}}_{\mathit{e}}$ and ${\mathit{V}}_{\mathit{h}}$. The dependence of the exciton binding energy upon the dot radius R and the offsets is studied for different sets of electron and hole effective masses.