Fundamental Semiconducting Properties of Perovskite Oxynitride SrNbO2N: Epitaxial Growth and Characterization

We carried out theoretical calculations and demonstrated epitaxial growth of SrNbO2N by RF reactive sputtering. The SrNbO2N (001) epitaxial film on a SrTiO3 (001) substrate had a single orientation and was of high crystalline quality. The film's band gap was experimentally determined as being 1.81 eV using a spectroscopic ellipsometer. Its transition type was indirect. In Hall effect measurements, the SrNbO2T film showed low Hall mobility despite our theoretical calculations showing the electron effective mass to be relatively low. Arrhenius plots of the Hall mobility and carrier concentration suggested the low mobility to result from conduction band bending due to the presence of grain boundaries.