Fabrication and Study of the Electronic Structure of МоO3/Мо Nanofilms

Abstract

The composition, the surface morphology, and the crystalline and electronic structure of МоО3 nanofilms are studied using a set of methods, namely, scanning electron spectroscopy and high energy electron diffraction, photoelectron spectroscopy, and secondary electron emission. These nanofilms are obtained by implanting $${\text{O}}_{{\text{2}}}^{{\text{ + }}}$$ ions into a Mo single crystal heated to Т = 850 K. Films with different thicknesses (~30, 60, and 90 A) are obtained at an ion energy of 1–5 keV and a dose of D = (4–8) × 1017 cm–2. It is shown that a continuous and homogeneous polycrystalline МоО3 film with a surface roughness of at most 1.5 nm is formed. The band gaps of these films are ~3.4 eV, and the widths of the conduction bands are 4.5 eV. It is discovered that there are four maxima of the density of electronic states in the valence band; probably, they are due to hybridization of the N5, N45, N4 energy levels of Mo with the L2, L23, and L3 energy levels of oxygen.