  We report the investigation of a single quantum dot charge storage device.
The device allows selective optical charging of a single dot with electrons,
storage of these charges over timescales much longer than microseconds and
reliable optical readout of the charge occupancy using a time gated
photoluminescence technique. This device enables us to directly investigate the
electric field dependent tunneling escape dynamics of electrons at high
electric fields over timescales up to 4 us. The results demonstrate that such
structures and measurement techniques can be used to investigate charge and
spin dynamics in single quantum dots over microsecond timescales.
