Abstract
A GaP n(+)p-diode containing In0.5Ga0.5As quantum dots (QDs) and an AlP barrier is characterized electrically, together with two reference samples: a simple n(+)p-diode and an n(+)p-diode with AlP barrier. Localization energy, capture cross-section, and storage time for holes in the QDs are determined using deep-level transient spectroscopy. The localization energy is 1.14(+/-0.04) eV, yielding a storage time at room temperature of 230(+/-60)s, which marks an improvement of 2 orders of magnitude compared to the former record value in QDs. Alternative material systems are proposed for still higher localization energies and longer storage times. (C) 2015 AIP Publishing LLC.