Fabrication of(Ga,Mn)As magnetic semiconductor quantum dots on Si substrates by droplet epitaxy

(Ga,Mn)As magnetic semiconductor quantum dots were fabricated on Si(001) substrates by droplet epitaxy using molecular-beam epitaxy. It is found that both the diameter and density of the(Ga,Mn)As quantum dots can be modulated by changing the amount of Ga deposited. The high-resolution transmission electron microscopy image shows that the dots possess a zincblende structure. The presence of ferromagnetic ordering with a Mn content of0.08 was observed, and the ferromagnetic transition temperature can be increased from approximately50 K to80 K by post-growth annealing.?2011 WILEY-VCH Verlag GmbH& Co. KGaA, Weinheim