First-principles prediction of a novel cadmium disulfide monolayer (penta-CdS2): Indirect to direct band gap transition by strain engineering

Using first principles calculation a novel two dimensional structure of Cadmium Disulfide (penta-CdS2) is predicted. The calculated cohesive energy of −3.61 eV/atom indicates the thermodynamic stability of the predicted monolayer. Furthermore, the kinetic stability of the monolayer is examined by phonon dispersion calculation. According to our calculations, penta-CdS2 monolayer is a semiconductor with an indirect band gap of 2.97 eV, which can be effectively engineered by employing external biaxial compressive and tensile strain, The results emphasize that penta-CdS2 monolayer as a wide band gap semiconductor can become a promising material for application in new generation of nano-optoelectronic devices.