[15P-T21-01] Surface Structure Reconstruction and Size Dependent Electronic Structure of CdSe
Keywords:CdSe, surface reconstruction, size dependent
In this work, the density functional theory (DFT) calculations were performed to systematically investigate the (111) and (110) surface reconstructions of CdSe and the electronic properties as the function of the layer size. It was found the reconstructed structure to be more stable. The calculated projected electronic density of states and electron local function indicate that electron pairing and new bond formation are responsible for the surface reconstruction. Moreover, we also discovered the size dependence of the band structure of the reconstructed (111) surface, that is, the (111) surface of CdSe changes from insulator to metal to topological insulator with the increasing layer size. The electronic properties of the reconstructed (110) surface structure are independent of the layer size and always remain semiconducting. It theoretically demonstrates that the surface structure and layer size could effectively modulate the electronic properties of the two-dimensional CdSe, revealing their applications in numerous practical fields.