Band Gap Engineering in Ultimately Thin Slabs of CdTe with Different Layer Stackings

Area of Science:

• Materials Science
• Condensed Matter Physics
• Solid-State Chemistry

Background:

• Ultrathin solid slabs display unique properties compared to their bulk counterparts.
• This phenomenon is observed in both traditional 3D materials and van der Waals (vdW) solids at the few-monolayer limit.

Purpose of the Study:

• To investigate the influence of thickness on the band gap of cadmium telluride (CdTe) slabs.
• To compare the band gap variations in the sphalerite and inverted phases of CdTe.

Main Methods:

• Density functional theory (DFT) calculations were employed.
• Band structures and partial densities of states were computed for various slab thicknesses.
• Thermodynamical stability of bulk vdW CdTe was verified.

Main Results:

• Band gap of CdTe slabs varies significantly with thickness, from one to several monolayers.
• Both sphalerite and inverted phases exhibit tunable band gaps.
• A wide range of band gaps can be achieved by controlling slab thickness.

Conclusions:

• Ultrathin CdTe exhibits thickness-dependent electronic properties.
• The tunable band gap of ultrathin CdTe makes it a promising candidate for electronic applications.
• This study provides insights into the potential of vdW CdTe for future electronic materials.