Suppression of lateral fluctuations in CdSe-based quantum wells

We report a reduction of inhomogeneous broadening in CdSe-related quantum w ells in ZnSe by employing a growth technique that uses a CdS-compound sourc e instead of the standard Cd elemental source for molecular-beam epitaxy. A ssisted by the low sticking coefficient of sulfur and possibly an exchange reaction between S and Se, only a small S contamination is observed. A comp arison with standard layers reveals an increase in quality and homogeneity by a strong reduction of the photoluminescence (PL) linewidth. Samples obta ined by our method show extremely little lateral confinement as indicated b y a lack of sharp single dot emission lines in micro PL and the absence of the extensive redshift observed in temperature dependent PL of fluctuating well potentials. (C) 2001 American Institute of Physics.