Optical spectroscopy of charged excitons in single quantum dot photodiodes- art. no. 195326

By means of photoluminescence spectroscopy we compare the bias dependent em issions of single quantum dots which are embedded in two differently design ed photodiode structures. Controlled single-electron charging allows to ide ntify neutral, single- and double-charged excitons; in the optical spectra of both samples. The strength of the tunneling coupling between the quantum dots and the diode's n region is found to have a strong influence on the o bserved spectral features-in particular, the parallel appearance of emissio n lines resulting from the radiative decay of differently charged quantum d ot states is suppressed in case of strong tunneling interaction.