Buried single CdTe/CdMnTe quantum dots realized by focused ion beam lithography

Buried single CdTe/CdMnTe quantum dots are realized by implantation-induced intermixing using a focused 100 keV Ga+ ion beam. For an implantation dose of 5x10(13) cm(-2) and an annealing temperature of 390 degrees C, a latera l potential depth of about 65 meV is obtained. By means of photoluminescenc e spectroscopy, the formation of zero-dimensional multiexcitons in single q uantum dots is investigated, yielding a biexciton binding energy of about 3 .5 meV. In addition, the occurrence of an excited biexciton transition in t he photoluminescence spectrum gives clear evidence of a suppressed exciton spin-flip process in quantum dots. (C) 1999 American Institute of Physics. [S0003-6951(99)01933-6].