Photoluminescence property of InAs quantum dots with InxGa1-x as layer inserted
Journal article, 2005
InAs quantum dots (QDs) have been grown on the GaAs(001) substrates by the method of molecular beam epitaxy. The emission of InAs QDs can be turned to about 1300 nm by the introduction of a 10 ML In0.4Ga0.6 As layer. The photoluminescence of the samples were studied before and after being treated by hydrogen plasma. The results show that the enhancement of the PL intensity after H-plasma treatment depends on the excitation power, from about a factor of 12 at the low excitation limit to about a factor of 2 at the highest excitation power used in this study, which are probably due to competition between carrier capture by nonradi-ative centers and InAs QDs. PL intensity variation with the chauge of time and temperature were also investigated, and the results of them clearly illustrate that there indeed exist interface defects, both on the interface between the InAs dots and surrounding layers and in the GaAs layers, which can be suppressed heavily by H-treatments so that the PL intensity can be enhanced greatly.