Optical marker of intrinsic point defects in ZnSe:Fe

Abstract

We reveal a new luminescent center with a narrow emission line at 0.681 eV in iron-doped ZnSe at low temperatures. In addition to the main emission line, a satellite peak with a maximum at 0.683 eV and a vibronic band characteristic of intracenter transitions were clearly observed. The spatial distribution of the luminescence signal near 0.681 eV is correlated with the well-known (5T2 → 5E) iron-related luminescence profile, but the detected center was not observed in the samples obtained by iron doping in a zinc atmosphere. Our data indicate the presence of the emitting complex defect composed of a zinc vacancy and an iron ion. According to ab-initio calculations, the emission line at 0.681 eV can be tentatively assigned to an intracenter transition in the spin majority channel of the Fe ion attached to a Zn vacancy. The detected complex can be used as an “optical probe” for intrinsic point defects in crystalline ZnSe:Fe.