Electrical characterization of self-assembled In 0.5 Ga 0.5 As/GaAs quantum dots by deep level transient spectroscopy

We have investigated electron emission from self-assembled In0.5Ga0.5As/GaAs quantum dots (QDs) grown by molecular-beam epitaxy (MBE). Through detailed deep level transient spectroscopy comparisons between the QD sample and a reference sample, we determine that trap D, with an activation energy of 100 meV and an apparent capture cross section of 5.4×10−18 cm2, is associated with an electron quantum level in the In0.5Ga0.5As/GaAs QDs. The other deep levels observed, M1, M3, M4, and M6, are common to GaAs grown by MBE.