ABSTRACT

The near-field spectra of InAs QDs for z-0 (no pressure) consist of a number of the sharp lines (up to twenty) corresponding to ground state emission of single QDs. The lines appear in two distinct energy ranges (1.31 and 1.42 eV for InAs/GaAs QDs and 1.55 and 1.64 eV for lnAs/ AlAs), which reflect the bimodal distribution of the dot sizes. Our magneto-PL [5] measurements show that the dots having higher emission energy correspond to the dots of the larger sizes and must, therefore, have an admixture of Ga. The halfwidth of the sharp lines is equal to the spectral resolution of our setup (0.2-0.4 meV).