Electronic structure and ferromagnetism of boron doped bulk and surface CdSe: By generalized gradient approximation and generalized gradient approximation plus modified Becke and Johnson calculations

Abstract

Using the full potential linearized augment plane wave method with the generalized gradient approximation (GGA) and GGA plus modified Becke and Johnson (GGA+mBJ) potential, the electronic structures and ferromagnetism for the boron doped bulk and surface CdSe are investigated. Calculations show that the substitutional boron for selenium in CdSe could induce spin polarized localized states in the gap and generate local magnetic moments 3.00 μB with one dopant atom. Energy difference between the antiferromagnetic and ferromagnetic phase suggests that BSe favors the ferromagnetic ground state. Electronic structures indicate the magnetic moments mainly provided by the doped boron atoms, and carriers mediated double exchange mechanism plays crucial role in forming the ferromagnetism. Ferromagnetic boron doped CdSe (100) films could be realized by using the high energy boron ions injection to form the non-surface doped configurations. The cadmium vacancy would reduce the ferromagnetism and lead the boron doped CdSe to magnetic metallicity. Formation energy for the four high symmetry doped configurations indicates BSe could be realized by using Cd-rich condition.