Miniband formation in InGaAs quantum dot superlattice

Abstract

We report the formation of a miniband in a quantum dot (QD) superlattice with 20-stack InGaAs QD layers, which we confirmed by the excitation power dependence in photoluminescence (PL) measurements. The PL peak of a QD superlattice shifts to a shorter wavelength as the excitation power is increased. The blueshifted energy of the PL peak is 8 meV for a QD superlattice with an interdot spacing of 3.5 nm, whereas the blueshift is not observed for a multistacked QD structure with an interdot spacing of 15 nm. The blueshifted energy becomes larger as the interdot spacing is reduced.