Molecular beam epitaxial growth of CdZnS using elemental sources

Abstract
We report on the first molecular beam epitaxial (MBE) growth of CdZnS on (100) GaAs substrates using elemental Zn, Cd, and S sources. Single crystal cubic CdZnS layers lattice matched to GaAs have been successfully prepared. The competition in incorporation between Cd and Zn under different sulfur flux conditions is investigated. Under appropriate growth conditions, the Cd1−xZnxS composition is directly related only to the ratio of the group II beam equivalent pressures. The background sulfur in the MBE growth chamber is found to etch the freshly thermally cleaned GaAs substrates and generate high density of pits on the surfaces. Methods to prevent the sulfur etching are also discussed.