Enhanced intraband Stark effects in stacked InAs/GaAs self-assembled quantum dots

We present a theoretical study of the electronic properties and intersubband optical transitions in vertically aligned double InAs self-assembled quantum dots (QDs) which are subject to an electric field along their growth axis. The electron properties are calculated as a function of the applied electric field by using an eight-band strain-dependent k.p Hamiltonian. Transitions between ground s states and excited p states are found to be almost three times stronger than in single dot, with strong field anisotropy. The system also exhibits field tunable transitions between the bonding and antibonding s states, with polarization along the growth axis. Midinfrared photodetectors consisting of vertically coupled double-quantum-dot layers are expected to exhibit enhanced sensibility and voltage tunability, compared to devices using single-quantum-dot layer. (C) 2001 American Institute of Physics.