Energy level engineering of coupled InAs quantum dot structures

Abstract

Photoluminescence, capacitance-voltage (C-V), and deep-level transient spectroscopy (DLTS) measurements were performed to investigate the optical and electrical properties of the vertically coupled InGaAs/mGaAsP/InP quantum dot (QD) system depending in an electric field. Two groups of activation energies, 0.36 - 0.37 eV and 0.41 - 0.44 eV for small and large QDs, appear in coupled QD samples by varying with the applied electric field. From the results, the quantum energy states of nearby QDs appear to couple and decouple as the gate bias conditions vary. ? 2007 American Institute of Physics.