Self-organized Ge quantum dots and its photoluminescence properties

摘要

The low dimensional system of Si and Ge has drawn great attention for their promising pho- toelectric properties. It has been theoretically predicted that when the size of quantum dots is smaller than a few nanometers, its band structure would change from indirect band gap to quasi- direct band gap, and the probability of radiative recombination transition transition can be increased drasti- cally. Among a variety of techniques to fabricate quantum dots ~[3-5, 7-10], such as lithography, selective molecular beam epitaxy (MBE), local MBE and self-organized growth, the self-orga- nized growth is a simple and effective method.