Epitaxial LaAlO3 thin film on silicon: Structure and electronic properties

Abstract

Epitaxial LaAlO3 films have been grown on Si (001) by molecular beam epitaxy with an ultrathin SrTiO3 seed layer. High resolution x-ray diffraction and transmission electron microscopy show the high quality epitaxial structure of LaAlO3 films, and the epitaxial relationship of LaAlO3 with Si is LaAlO3(001)‖Si(001) and LaAlO3[100]‖Si[110]. The band gap of epitaxial LaAlO3 films was measured to be 6.5±0.1eV from O 1s loss spectra. Band offsets between crystalline LaAlO3 films and Si were determined to be partitioned equally with 2.86±0.05eV for valence-band offset and 2.52±0.1eV for conduction-band offset by using x-ray photoelectron spectroscopy.