Effects of electric field and Coulomb interaction on the interband transitions of InAs self-assembled quantum dots: A study by modulation reflectance spectroscopy

We employ the conventional electroreflectance techniques to investigate the electric field effects on the interband transitions of InAs quantum dots (QDs) in a p-i-n diode. The electric field induced energy shift reveals an asymmetric quantum-confined Stark effect, which indicates that the QDs have a nonzero built-in dipole moment. Secondly, electron-filling reflectance was applied to investigate the Coulomb charge effects on the interband transitions of InAs QDs embedded in a charge tunable p⁺-n structure. Effects of Pauli blocking and many-body Coulomb interactions on QDs are observed and discussed.