Annealing of Radiation Damage in ZnSe

Abstract

Electron bombardment of ZnSe at 80°K results in the production of two fluorescence bands at 5460 and 5850 Å. The threshold for damage at 80°K is 240 keV. When the sample is cooled to 4.2°K following bombardment at 80°K the fluorescence spectrum changes, reflecting the temperature dependence of the fluorescence; the peak at 5460 Å disappears, a new one at 6400 Å appears, and the peak at 5850 Å shifts slightly to a shorter wavelength. When the crystals are bombarded at 10°K, fluorescent peaks at 6100 Å and 6400 Å are produced. The threshold for radiation damage at 10°K is 195 keV. The radiation damage at high energies at 10°K anneals in three stages, one at about 60°K, another at 90°K, and the final one at 135°K. The fluorescence spectrum changes following each of the first two annealing stages and disappears completely after the third annealing stage. With equal bombardment times, the fluorescence spectrum at 10 and at 80°K is identical, whether the crystal has been bombarded at 10°K and annealed at 90°K, or bombarded at 80°K without annealing. A Meecham and Brinkman plot has been used to determine the activation energies and the order of reaction of the three annealing stages.