Energy level engineering in InAs quantum dot stacks embedded in AlAs/GaAs superlattices

We present a new method to design the energy level scheme of quantum dot (QD) structures by combining band gap engineering with the self-organized growth of (QDs). With the embedding of QDs in two-dimensional supperlattices optical transition energies, ionization energies and the absorption properties of this system can be adjusted. This scheme is applied for novel photodetectors made of InAs QDs embedded in an AlAs/GaAs superlattice, and the absorption energy is tailored by changing the superlattice period. Moreover, the dark current of these devices is reduced by more than one order of magnitude compared to devices without a superlattice.