Formation of Lateral Low Density In(Ga)As Quantum Dot Pairs in GaAs Nanoholes

In this work we present a growth procedure to form lateral In(Ga)As quantum dot pairs by using a low density, 2 × 108 cm-2, GaAs nanohole template previously formed in situ by droplet homoepitaxy. In particular, by changing the arsenic pressure at which InAs is grown on the template, we demonstrate the possibility to select the formation of single quantum dots (QD) or QD pairs inside each of the nanoholes. In the case of QD pairs, the ensemble photoluminescence (PL) as a function of excitation power and temperature reveals spectral signatures typical of laterally coupled nanostructures.