Electrical characterization of all-epitaxial Fe/GaN(0001) Schottky tunnel contacts

We analyze the properties of Fe Schottky contacts prepared in situ on n-type GaN(0001) by molecular beam epitaxy. In particular, we investigate the suitability of these epitaxial Fe layers for electrical spin injection. Current-voltage-temperature measurements demonstrate pure field emission for Fe/GaN:Si Schottky diodes with [Si] = 5 $\times$ 10${}^{18}$ cm${}^{-3}$. The Schottky barrier height of the clean, epitaxial Fe/GaN interface is determined by both current-voltage-temperature and capacitance-voltage techniques to be (1.47 $\pm$ 0.09) eV.