ABSTRACT
This chapter presents some of the effects due to the electron and hole exchange interaction in quantum dot molecules (QDMs) and demonstrates control of the exchange splitting energy. It discusses the electron and hole exchange interaction can be varied using an applied electric field. The spin-dependent interactions in QDMs were investigated through polarization-resolved photoluminescence spectra, as they directly couple to the spin states of the carriers while conserving the angular momentum. The most attractive feature that differentiates the QDMs from single quantum dots (QDs) is the strong electric field dependence of the indirect exciton states where the electron and hole reside in different QDs within the QDM. Quantization energies of the individual layers of QDs are controlled by the indium flush technique during the growth. In chargetunable QDs, many efforts have been undertaken to investigate the optical properties of excitonic states through polarization-resolved measurements.
