Effect of thermal annealing on the photoluminescence of β-FeSi2 films on Si substrate

In order to improve the photoluminescence (PL) of semiconducting β-FeSi2 films, as-grown films were thermally annealed under various conditions. The films were fabricated either by an ion beam sputter deposition (IBSD) or a molecular beam epitaxy (MBE) method. For both IBSD-grown and MBE-grown films, high temperature annealing in a flow of Ar gas or air led to drastic enhancement of PL intensity. Furthermore, PL characteristics were found to depend on the annealing atmosphere, where it was shown that air was more effective than Ar gas.