Influence of doping time on spatial distribution of luminescence intensity in ZnSe:Fe

Highlights: • The crystals of ZnSe were doped with Fe for different times (8–240 h) at T = 1000 °C. • The strip-like areas with high intensity of green and red luminescence parallel to the doping surface were observed. • The distance from doping surface to areas with high intensity is increased with increasing of doping time. • The green and red luminescence areas is interpreted by co-diffusion of iron and at least 2 types of defect centers. • The diffusion coefficients of defective-impurity centers greater than that of iron. For ZnSe crystals doped with Fe by a high-temperature diffusion technique, the influence of annealing time on the positions of strip-like areas with a high intensity of luminescence at wavelengths of 521 and 715 nm parallel to the doping surface is studied. It is found that the distance between the doping surface and the strip-like areas increases with increasing doping time. A good description of the results is obtained under the assumption of simultaneous diffusion of Fe ions and two different defect/impurity centers. The formation of spatial strip-like areas is shown to be a general phenomenon arising in the co-diffusion of several types of recombination centers.