Figure 2

TEM image and EDS results. (a) TEM image of a portion of the cleaved cross section of a QDCL active region. (b) The enlargement image of a portion of Figure 2a for clarity, and the white line gives a clear indication of QDs distribution parallel to the growth layer. (c) Indium relative content along the indicated white line in Figure 2b measured by X-ray energy dispersion spectra.