Abstract

The effect of matrix-dependent strain in self-assembled InAs/GaAs quantum dots grown by MOCVD were studied using photoluminescence (PL) measurements. Samples were prepared to study the strain effect induced by the so called strain-buffer layer and strain-cap layer. The PL results showed that the strain-cap layer can reduce the residual hydrostatic strain effectively, the emission wavelength being tuned from 1.258 μm to 1.366 μm when the In composition in the 5nm InxGa1-xAs strain-cap layer increased from x=0 to x=0.25. Nevertheless, the 5nm InGaAs strain-buffer layer with the same In composition changes resulted in only 10 nm red shift of the emission wavelength with a significant decrease of PL intensity.

© 2005 Optical Society of America