Formation of self-organized CdSe quantum dots on ZnSe(100) surfaces by molecular beam epitaxy

We have investigated the formation of self-organized CdSe quantum dots (QDs ) on ZnSe(100) surfaces with the use of photoluminesence (PL) and transmiss ion electron microscopy (TEM). TEM measurement reveals that CdSe grows two- dimensionally on ZnSe(100) surfaces in the initial stages, and then at arou nd 1.8 monolayer (ML), CdSe grows three-dimensionally and begins to nucleat e QDs. Coherent CdSe QDs are naturally formed on ZnSe surfaces, when the th ickness of CdSe layers is about 2 ML. The plan-view TEM images reveal that CdSe QDs have a relatively narrow distribution of QD size, and that the den sity and diameter of CdSe QDs are about 10(10) cm(-2) and 30 nm, respective ly. Moreover, CdSe QDs exhibit a strong green emission even at room tempera ture. (C) 2000 Elsevier Science B.V. All rights reserved.