Photoluminescence study of the In0.3Ga0.7As surface quantum dots coupling structure

Photoluminescence (PL) was investigated as functions of the excitation intensity and temperature for a coupling surface quantum dots (SQDs) structure which consists of one In0.3Ga0.7As SQDs layer being stacked on multi-layers of In0.3Ga0.7As buried quantum dots (BQDs). Accompanied by considering the localized excitons effect induced by interface fluctuation, carrier transition between BQDs and SQDs were analyzed carefully. The PL measurements confirm that there is a strong carrier transition from BQDs to SQDs and this transition leads to obvious different PL characteristics between BQDs and SQDs. These results are useful for future application of SQDs as surface sensitive sensors.