Publication Date:
2016-03-16
Description:
InAs quantum-dot structures were grown using a GaAs 1− x Sb x matrix on a GaAs(001) substrate. The use of GaAs 1− x Sb x for the buffer and cap layers effectively suppressed coalescence between dots and significantly increased the dot density. The highest density (∼3.5 × 10 11 /cm 2 ) was obtained for a nominal 3.0 monolayer deposition of InAs with an Sb composition of x = 13–14% in the GaAs 1− x Sb x matrix. When the Sb composition was increased to 18%, the resulting large photoluminescent red shift (∼90 meV) indicated the release of compressive strain inside the quantum dots. For x 〉 13%, we observed a significant decrease in photoluminescence intensity and an increase in the carrier lifetime (≥4.0 ns). This is attributed to the type-II band alignment between the quantum dots and matrix material.
Print ISSN:
0021-8979
Electronic ISSN:
1089-7550
Topics:
Physics
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