Correlation effects for highly Cr doped ZnSe

Abstract

A study of the electronic properties and correlation effects of Cr in ZnSe using firstprinciples is presented. These materials have potential technological applications formid-infrared lasers, solar cells and spintronics. They have an intermediate band in the hostsemiconductor band gap with the Fermi energy located within this intermediate band fora sufficiently high density of Cr substituting the Zn atoms. An analysis of theelectronic properties is carried out using the local density approximation with aHubbard term to improve the description of this intermediate band. The main effectswhen the Hubbard term is included are an increase in the bandwidth and themodification of the relative composition of the d and p Cr transition metal orbitals.From the results, the intermediate band is not split, creating two bands, for theHubbard term between 0 and 9 eV. The relaxing of the atomic configurations causes aslight increase in the intermediate bandwidth and a decrease in the gaps. Theeffect of the correlation is lower than for other zinc chalcogenides doped with Cr.