In this article, density functional theory（DFT） based on generalized gradient approximation（GGA）and GGACU, U is Hubbard term, is used to study the electronic properties of CdS doped with different dopants（Cr, Mn...In this article, density functional theory（DFT） based on generalized gradient approximation（GGA）and GGACU, U is Hubbard term, is used to study the electronic properties of CdS doped with different dopants（Cr, Mn）. The calculations are carried out for Mn-doped CdS, Cr-doped CdS, and co-doping of Mn/Cr in CdS simultaneously. It is found that hopping of electrons is possible with Cr：CdS and Mn：Cr：CdS while Mn：CdS does not allow the hopping of electrons. Moreover, double exchange interactions are observed in Cr：CdS and d-d superexchange interactions are observed in Mn：CdS. Now the problem becomes interesting when one magnetic ion（Cr） supporting double exchange interactions and another ion（Mn） supporting d-d super-exchange interactions are doped simultaneously in the same system（CdS）. The co-doped CdS is more stable even at high Curie temperature due to p-d double exchange interactions and d-d super exchange interactions. Furthermore, the Cr-3d and Mn-3d states present in-between the band gap are responsible for inner shell transitions and hence for optical properties.Therefore, the co-doped system is taken into account to enhance its applications in the field of spintronic and magneto-optical devices.展开更多
文摘In this article, density functional theory（DFT） based on generalized gradient approximation（GGA）and GGACU, U is Hubbard term, is used to study the electronic properties of CdS doped with different dopants（Cr, Mn）. The calculations are carried out for Mn-doped CdS, Cr-doped CdS, and co-doping of Mn/Cr in CdS simultaneously. It is found that hopping of electrons is possible with Cr：CdS and Mn：Cr：CdS while Mn：CdS does not allow the hopping of electrons. Moreover, double exchange interactions are observed in Cr：CdS and d-d superexchange interactions are observed in Mn：CdS. Now the problem becomes interesting when one magnetic ion（Cr） supporting double exchange interactions and another ion（Mn） supporting d-d super-exchange interactions are doped simultaneously in the same system（CdS）. The co-doped CdS is more stable even at high Curie temperature due to p-d double exchange interactions and d-d super exchange interactions. Furthermore, the Cr-3d and Mn-3d states present in-between the band gap are responsible for inner shell transitions and hence for optical properties.Therefore, the co-doped system is taken into account to enhance its applications in the field of spintronic and magneto-optical devices.
