Temperature and electric field dependence of the carrier emission processes in a quantum dot-based memory structure

Hole emission processes from self-organized GaAs(0.4)Sb(0.6)/GaAs quantum dots embedded in a p-n diode are studied by capacitance-voltage spectroscopy. The method introduced allows the investigation of the temperature and electric field dependence of carrier emission with time constants from below nanoseconds up to thousands of seconds. Different emission processes are clearly distinguished, such as tunneling, phonon-assisted tunneling, and thermal activation, each important for quantum-dot-based memory structures. The erase time was determined to 1.5 ms for an electric field of about 200 kV/cm. At 500 kV/cm, 10 ns are predicted sufficient for fast erasing.