Photoluminescence of a single InAs quantum dot molecule under applied electric field

We study the electronic coupling between two vertically stacked InAs quantum dots, which are embedded in the center of a $n-i-n$ structure. We use a microphotoluminescence setup to optically isolate a single quantum dot pair and measure the time-averaged photoluminescence under an applied vertical electric field. We find that field tunable coupling between excited states of the two quantum dots leads to charge transfer from one dot to the other. We model the spectra including simultaneously the field-dependent charge transfer and exciton capture rates, and the many-body spectra of the quantum dot molecule for different carrier configurations.