Magnetic and optical properties of self-organized InMnAs quantum dots

Ten layers of self-assembled InMnAs quantum dots with InGaAs barrier were grown on high resistivity (100) p-type GaAs substrates by molecular beam epitaxy (MBE). The presence of ferromagnetic structure was confirmed in the InMnAs diluted magnetic quantum dots. The ten layers of self-assembled InMnAs quantum dots were found to be semiconducting, and have ferromagnetic ordering with a Curie temperature, T-C=80 K. It is likely that the ferromagnetic exchange coupling of sample with T-C=80 K is hole mediated resulting in Mn substituting In and is due to the bound magnetic polarons co-existing in the system. P-L emission spectra of InMnAs samples grown at temperature of 275, 260 and 240 degrees C show that the interband transition peak centered at 1.31 eV coming from the InMnAs quantum dot blueshifts because of the strong confinement effects with increasing growth temperature. (C) 2010 Elsevier Ltd. All rights reserved.