Ab initio calculations of Structures, Energetics, and Electronic properties of bulk and nanosheet of CdX( X= CdS, CdSe,and CdTe) compounds

We studied systematically the structural and electronic properties of chalcogenides CdX (X= CdS, CdSe, and CdTe) for both bulk and nanosheet states. In this paper, the generalized gradient approximation (GGA) is used for the exchange-correlation potential calculation. The ground state properties are determined for the bulk materials CdX in cubic phase and sheet materials CdX in hexagonal structure by using the Quantum-ESPRESSO ab initio simulation package based on pseudo potential method within density functional theory(DFT). The calculated lattice constant, electronic band structure, partial and total density of states for bulk are in good agreement with available experimental and theoretical results. we also compared these properties for nanosheet states with theoretical results. The results show that bulk-nanosheet these compounds are semiconductors and owing to their direct larg gap. We find that CdX in the nanosheet state has a larger band gap than the one in the bulk state

Keywords:

Electronic structure , bulk , nanosheet , Quantum-ESPRESSO