Structural and optical properties of InSb quantum dots for mid‐IR applications

We investigate the MBE growth and properties of Sb‐based nanostructures, very promising candidates as active material for mid infrared light sources operating between 3 and 5 μm. We show that the key feature for the fabrication of highly dense and optically efficient InSb quantum dots is the control of In‐adatoms mobility. We obtain defect‐free nanostructures with a density as high as 8 × 1010 dots/cm2 together with improved performance in terms of optical emission. Photoluminescence and electroluminescence emissions, peaked at around 360 meV, have been measured which exhibit a linewidth of 47 meV at 90 K. The emission is detected up to room temperature, with an intensity quenching factor as low as 4 from 90 K to 300 K, demonstrating good thermal stability of the material. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)