Band Gap Variation of 2D CdTe Slabs in the Sphalerite Phase and in the Phase with Boundary Chalcogen Atoms

Reducing the thickness of semiconductors to the limit of a few monolayers often leads to emergence of new properties. In this work, the thickness dependence of the band gap of cadmium telluride slabs in both the sphalerite phase and in the inverted phase is studied using the density functional theory method. The sphalerite phase is characterized by Cd–Te–Cd–Te alternating atomic planes, while in the inverted phase the order of planes is Te–Cd–Cd–Te. It is shown that using slabs with a thickness of one to several monolayers variable-gap structures can be fabricated.