Fabrication of IR windows grade zinc selenide by the reactive diffusive process

摘要

The preparation of infrared windows grade zinc selenide (ZnSe) by the reactive diffusion process between liquid zinc and selenium was the goal of present work. In this regards, high purity zinc and Se elements with a nominal composition of Zn50Se50 were capsulated in quartz ampoule and annealed in the temperature range of 550-950 degrees C. The wurtzite structure of zinc selenide phase was successfully obtained during annealing process beyond 750 degrees C. The hexagonal structure of zinc selenide was an unstable phase and totally transformed to the cubic construction by increasing the annealing temperature (950 degrees C) that is appropriate for infrared windows application. The formation of zinc selenide phase during the annealing process has been performed by the development of an unceasing layer of porous zinc selenide compound in zinc/selenium interface. The formation of porous zinc selenide can be associated to the different diffusion constants of selenium and zinc atoms in zinc selenide lattice based on the Kirkendall theory.