Impact of Nitrogen incorporation on pseudomorphic site-controlled quantum dots grown by Metalorganic Vapour Phase Epitaxy

We report on some surprising optical properties of diluted nitride InGaAs(1-epsilon)N(epsilon)/GaAs (epsilon << 1) pyramidal site-controlled quantum dots, grown by metalorganic vapor phase epitaxy on patterned GaAs (111)B substrates. Microphotoluminescence characterizations showed antibinding exciton/biexciton behavior, a spread of exciton lifetimes in an otherwise very uniform sample, with unexpected long neutral exciton lifetimes (up to 7 ns) and a nearly zero fine structure splitting on a majority of dots. (C) 2010 American Institute of Physics. (doi:10.1063/1.3481675)