Metamorphic InAs/InGaAs Quantum Dots Photoresponsive in the 1.3-1.55 ?m Window

Photoelectric properties of metamorphic InAs/InxGa1-xAs quantum dot (QD) nanostructures were studied at room temperature, employing photoconductivity and photoluminescence spectroscopies, electrical measurements, and theoretical modeling. Samples with different stoichiometry of InxGa1-xAs cladding layer have been grown. InAs/In0.15Ga0.85As QD structure was found to be photosensitive in the telecom range at 1.3 ?m. As x increases, a redshift was observed for all the samples, the structure with x = 0.31 was found to be sensitive near 1.55 ?m telecom window. Only a slight decrease in QD photoconductivity was recorded for increasing x, thus confirming a good photoresponse comparable with the one of In0.15Ga0.85As structures and of GaAs-based QD nanostructures. Also, the photoconductivity reduction correlate with the similar reduction of photoluminescence intensity.