CW photoluminescence determination of the capture cross-section of self-assembled InAs quantum dots

We have performed a systematic photoluminescence (PL) study on a well-characterized InAs self-assembled quantum dot sample grown on a (0 0 1) GaAs substrate with a quantum dot density gradient across the surface ranging from 0 to View the MathML source. The PL measurements were carried out at View the MathML source at different locations of the sample surface. The data analysis reveal that the quantum dot (QD) carrier capture rate scales linearly with the QD density for densities below View the MathML source and saturates beyond this critical density. The saturation has been interpreted to arise from the overlap of the carrier capture cross-section of individual neighboring dots. Therefore, from the inverse of the critical quantum dot density we have determined the capture cross-section of each QD to be View the MathML source.