Growth and optical characterization of InAsN quantum dots

Self-assembled InAsN quantum dots (QDs) have been grown by rf-plasma-assisted molecular beam epi-taxy (RF-MBE) on GaAs(001) substrates via a 2-monolayer (ML)-thick InAs wetting layer. The InAsN QDs are typically 30-70 nm in diameter and 3-7nm in height. The dot density was 3.6 × 10 ⁹-2.3 × 10¹⁰ cm^-2 for the fluxes corresponding to the nominal thicknesses of 3.0-4.0 MLs. As the nominal thickness increases, the dot density increases, while the diameter decreases. The low-temperature (10 K) photoluminescence (PL) of the QD samples shows emission spectra in the wavelength range of 1.2-1.6 μn apparently caused by the N incorporation (0.8-2.0%) into the QDs. The QD size distribution causes broad emission spectra.