We report on the growth of the compound semiconductor MgTe as well as
the ternary alloy Cd1-xMgxTe by molecular beam epitaxy. This is to our
knowledge the first time that this material has been grown by any epi
taxial technique. Bulk MgTe, which is hygroscopic, has a band gap of 3
.0 eV and crystallizes usually in the wurtzite structure. Pseudomorphi
c films were grown on zincblende CdTe substrates for a MgTe thickness
below a critical layer thickness of approximately 500 nm. In addition.
Cd1-xMgxTe epilayers were grown with a Mg concentration between 0 and
68%, which corresponds to a band gap between 1.5 and 2.5 eV at room t
emperature. The crystalline quality of the layers is comparable to CdT
e thin films as long as they are fully strained. The lattice constant
of zincblende MgTe is slightly smaller than that of CdTe, and the latt
ice mismatch is as low as 0.7% In addition highly n-type CdMgTe layers
were fabricated by bromine doping. The tunability of the band gap as
well as the rather good lattice match with CdTe makes the material int
eresting for optoelectronic device applications for the entire visible
range.