Structural, electronic, and optical properties of two-dimensional bilayer MgCl2 intercalated with Be and Mg single atom: Insulator to semiconductor transformation

Abstract

The intercalation of alkaline earth metals Be and Mg single atoms in the two-dimensional (2D) bilayer MgCl₂ (B-MgCl₂) system has been investigated in the present study, showing their effect on the structural, electronic, and optical characteristics using density functional theory (DFT) computation. The electronic behavior of B-MgCl₂ has been identified as that of an insulator. In contrast, the behavior of the Be and Mg-intercalated B-MgCl₂ shifts to that of a narrow band gap semiconductor, with the band gap measured at 1.00 eV and 0.98 eV for Be-MgCl₂ and Mg-MgCl₂, respectively. This notable change in electronic behavior presents intriguing opportunities for practical applications in optoelectronics and semiconductor devices. Moreover, the intercalation of Be and Mg atoms significantly influences the built-in electric field of the B-MgCl₂ system. The rise in the built-in electric field after the intercalation of Be and Mg atoms further emphasizes the potential for manipulating the electronic properties of this system for specific applications, potentially enabling improved charge transport and optoelectronic properties. Besides altering the electronic band structure, the intercalation of Be and Mg single atoms into the bilayer MgCl₂ system also induces prominent peaks in the infrared, visible, and ultraviolet (UV) regions of the solar spectrum. These observed optical characteristics represent a crucial aspect in the development of intercalation compounds for optoelectronic nanodevices, as they offer enhanced absorption and emission properties that can be harnessed in a wide range of technological applications and opening up avenues for innovation in the field of semiconductors.