Assessment on the use of the amorphous semiconductor theory for the analysis of oxide films

The Amorphous Semiconductor Schottky Barrier Approach to Study the Electronic Properties of Anodic Films on Ti

“…In fact, the constraint U E ≥ ψ C (ω) + The DOS, extracted according to Equation 10, is reported in Figure 6b for all the investigated frequencies. As discussed previously, 8 the value of N(E ω ) as a function of the energy (E -E F ) is a good approximation to the value of DOS distribution. Figure 6b shows that the DOS is not constant and can be well fitted by a Gaus- sian distribution peaked at around 0.25 eV from E F .…”

“…The continuous lines overlapped to the experimental points result from a best fitting procedure according to Equation 8, assuming ε (a-TiO 2 ) = 50 32 at all investigated frequencies as requested from the theory. 8 The fitting of the differential capacitance curves is good in the whole range of investigated frequencies, provided that the exploited potential is lower than the value corresponding to a space charge region width, x SC , ≤ 0.70 d ox (d ox = oxide thickness). A film thickness of ∼18 nm is estimated for the TiO 2 grown in these conditions in good agreement with data reported in literature for Ti anodizing in similar conditions.…”

“…Previous papers described in detail how the characterization of semiconducting passive film/electrolyte junction based on the use of simple Mott-Schottky (M-S) analysis to get information on the solid state properties of anodic films presents some drawbacks. [4][5][6][7][8] In order to account for the amorphous or scarcely crystalline nature of anodic oxide films, an approach was suggested for the description of physicochemical properties of semiconducting passive films based on the theory of amorphous semiconductors (a-SC) Schottky barrier. [9][10][11][12][13] In more recent papers [5][6]8 the results of the a-SC Schottky barrier theory were extended to the case of thin amorphous semiconductors, i.e.…”

“…[4][5][6][7][8] In order to account for the amorphous or scarcely crystalline nature of anodic oxide films, an approach was suggested for the description of physicochemical properties of semiconducting passive films based on the theory of amorphous semiconductors (a-SC) Schottky barrier. [9][10][11][12][13] In more recent papers [5][6]8 the results of the a-SC Schottky barrier theory were extended to the case of thin amorphous semiconductors, i.e. when the space charge region width of the semiconductor is close to the film thickness.…”

Determination of the Flat Band Potential of Nanoparticles in Porous Electrodes by Blocking the Substrate–Electrolyte Contact

“…By describing the density of states (DOS) distribution of the nanoparticle electrodes with the theory of amorphous semiconductor junctions (a-SC) and simulating the ac voltage response of the system, both effects are explained. The approach is based on the original work of Losee, and the equations used for the numerical solution are described in detail elsewhere. − …”