In the present work, we report on the investigation of a p-n heterostructur
e with InAs/GaAs quantum dots (QD) by capacitance-voltage and deep level tr
ansient spectroscopy. We have observed controllable and reversible metastab
le population of the energy states of quantum dots and interface in the str
ucture containing one plane of InAs QDs as a function of temperature of iso
chronous annealing as well as under bias-on-bias-off cooling conditions and
white light illumination. This effect was attributed to the change in the
Fermi level position due to the hole capture on self-trapped defects simila
r to the DX center in GaAs after isochronous annealing and white light illu
mination.