Electrochemical studies of the electron states of disordered electrochromic oxides

Charge transport between localized states in lithium-intercalated amorphous tungsten oxide

“…A major effect of stoichiometry on the DOS for WO y is observed. The data for y = 2.89 and 2.93 display the qualitative features seen in electronic structure computations and in previous experiments [19,21], although more smeared out. On the other hand the film with y = 2.63 displays strong peaks at 0.2-0.4 eV above the band edge.…”

“…The stretched exponential decay of the temperature-dependent conductivity is related to two parameters, namely the density-of-states (DOS) at the Fermi level and the localization length. As mentioned above, it was recently shown [20,21] that the DOS can be obtained from electrochemical steady-state potential curves by intercalation spectroscopy. This makes it possible to derive the electron localization length directly from the temperature dependence of conductivity in the VRH regime.…”

Determination of solid phase chemical diffusion coefficient and density of states by electrochemical methods: Application to iridium oxide-based thin films

“…13 Hence, the GITT and CP methods have been used to study the electronic DOS in the vicinity of the Fermi level for several transition metal oxides. 14,15 There are other methods to determine the DOS experimentally, especially electron and x-ray spectroscopic methods, [16][17][18] and theoretical ab initio calculations can be used too. [19][20][21][22] A detailed knowledge of the DOS is especially interesting for EC materials, since the coloration in the visible wavelength region involves electron excitations between filled and empty states by, for example, an intervalence charge transfer mechanism.…”

Electrochemical measurements of the electronic density of states

“…The side reactions are probably of less importance in CP, because of slow diffusion of ions to the reaction/trapping sites. Figure 4 shows another example of qualitative agreement between the experimental EDOS and computed DOS, namely for CeO 2 [13]. A puzzling result is that the EDOS 6 resembles not the total DOS of the lowest Ce 4f conduction band, but instead the DOS of an admixture of oxygen 2p states [13].…”

“…Figure 4 shows another example of qualitative agreement between the experimental EDOS and computed DOS, namely for CeO 2 [13]. A puzzling result is that the EDOS 6 resembles not the total DOS of the lowest Ce 4f conduction band, but instead the DOS of an admixture of oxygen 2p states [13]. The reason for this is not known, but it should be noted that the inserted Li ions will most likely bind to oxygen ions in the material.…”