Quantum-confined Stark effect in interdiffused quantum dots

The authors theoretically investigate the effects of isotropic composition interdiffusion on the optical transition energy of quantum-dot (QD) structures under an electric field. Their three-dimensional QD calculation is based on coupled InAs/GaAs QDs arranged periodically in a tetragonal superlattice, taking into account the effects of finite band offset, valence-band mixing, strain, effective mass anisotropicity, and different QD shapes. The electron and hole Hamiltonians with the interdiffusion effect are solved in the momentum space domain. The enhanced Stark shifts and the reduced built-in dipole moment have been found for the interdiffused QD structures. (c) 2006 American Institute of Physics.