A carrier escape study from InAs self-assembled quantum dots by photocurrent measurement

We report investigations of the carrier escape from InAs self-assembled qua ntum dots. Based on measurements of the temperature-dependent photocurrent, the escape of photoexcited carriers is found to be dominated by the hole e scape process. The main path for this hole escape was further clarified, wh ich is a thermally assisted hole tunneling, from the dot level to the GaAs barrier via the wetting layer as an intermediate state. The size: selective tunneling effect and the carrier redistribution effect an discussed and co mpared with temperature-dependent photoluminescence measurements.