Computer analysis of an influence of oxygen vacancies on the electronic properties of the SnO₂ surface and near‐surface region

Abstract

An influence of the surface stoichiometric defects on the electronic and electrical properties of SnO2 layers has been studied by means of computer simulation. The surface potential and in‐depth potential profiles in the accumulation region have been rigorously computed at various temperatures (from 400 to 900 K). The behaviour of both the surface and bulk Fermi level position versus temperature has been analysed. Furthermore, in‐depth profiles of carrier concentration and the surface potential as well as the SnO2 layer conductance for different surface donor density of state have been calculated. It has been found that the surface reduction and bulk donor concentration (in the range from 3 × 1014 to 3 × 1018 cm–3) are strongly correlated with the development of near‐surface accumulation region and thus modification of the layer electrical parameters. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)

Numerical Analysis of Oxygen Adsorption on SnO2Surface Using Slab Geometry

“…The material is being used as a photocatalyst and a gas sensor and in optical devices [1][2][3]. In all these applications, the surface-related phenomena play a major role and become particularly important for nanomaterials, in which surface-to-volume ratio is much higher [4][5][6]. Precise numerical model of electrical properties of near-surface layer of SnO 2 grains is fundamental for improving sensitivity and selectivity of SnO 2 based gas sensors [6].…”

Nanoparticle Thin Films for Gas Sensors Prepared by Matrix Assisted Pulsed Laser Evaporation

“…Generally for SnO 2 we can put E g =3.6 eV, ε =12, m e =0.3 m 0 and m h =0.8 m 0 , where m 0 is the free electron mass [28]. The above relation is plotted in Figure 9.…”

“…The dependence of absorption onset on the particle size is based on the effective mass approximation and the increase in the optical band gap of a nanocrystalline semiconductor may be described by the relation [ 27 ]: where E * and E g are the cluster and bulk-state band gap energies, respectively; m e and m h are the electron and hole effective mass, respectively; ε is the dielectric constant of the semiconductor and R is the average particle size, while h is the Plank constant and e is the electron charge. Generally for SnO 2 we can put E g =3.6 eV, ε =12, m e =0.3 m 0 and m h =0.8 m 0 , where m 0 is the free electron mass [ 28 ]. The above relation is plotted in Figure 9 .…”

Numerical analysis of an influence of oxygen adsorption at a SnO2 surface on the electronic parameters of the induced depletion layer

“…Adamowicz et al [10] focused on explaining the relationship between crystallographic structure, chemical composition and surface morphology and electron properties of SnO 2 thin films (carrying out gas tests). Furthermore, Izydorczyk et al [11] proved the strong influence of the SnO 2 surface and bulk stoichiometric defects (oxygen vacancies) on the development of a near-surface accumulation region and thus modification of the electronic parameters of the surface space-charge region, including the surface potential, surface charge, surface Fermi level and electron conductivity behaviour versus temperature.…”