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

We present a theoretical study of the electronic properties and intersubban d optical transitions in vertically aligned double InAs self-assembled quan tum dots (QDs) which are subject to an electric field along their growth ax is. The electron properties are calculated as a function of the applied ele ctric field by using an eight-band strain-dependent k.p Hamiltonian. Transi tions between ground s states and excited p states are found to be almost t hree times stronger than in single dot, with strong field anisotropy. The s ystem also exhibits field tunable transitions between the bonding and antib onding s states, with polarization along the growth axis. Midinfrared photo detectors consisting of vertically coupled double-quantum-dot layers are ex pected to exhibit enhanced sensibility and voltage tunability, compared to devices using single-quantum-dot layer. (C) 2001 American Institute of Phys ics.