Energy transfer between Co~(2+) and Fe~(2+) ions in diffusion-doped ZnSe

摘要

Absorption, photoluminescence (PL), and time-resolved PL measurements were applied to samples of polycrystalline ZnSe which were diffusion doped with iron or with cobalt or codoped with both iron and cobalt. Characteristic emission and absorption features due to Co~(2+) and Fe~(2+) were observed in the visible and infrared regions. In the spectral region near 3 μm, a Co~(2+) emission overlaps completely with an Fe~(2+) absorption and energy transfer occurs. Using PL lifetime data, a decrease in the Co~(2+) lifetime of ～300 μs to less than 100 μs was observed. This decrease in lifetime indicates that the nature of the energy-transfer process is nonradiative. The energy-transfer rate decreases with temperature, as expected for the nonradiative electric dipole-dipole interaction. The temperature dependences of both Co~(2+) and Fe~(2+) emissions are described.