Band tails in hydrogenated amorphous silicon and silicon-germanium alloys

Study of the Hole Transport Processes in Solution‐Processed Layers of the Wide Bandgap Semiconductor Copper(I) Thiocyanate (CuSCN)

“…The DOS characteristic energy is also found to monotonically decrease with the decreasing temperature as plotted in Figure 6b. Similar behavior has also been seen in the analysis of the optical absorption coefficient of a-Si:H by Cody et al [45] and clarified further by Aljishi et al [46] using photoelectron spectroscopy. Both reports also show the 'freeze-in' of the localized states, which is the leveling off of t E to a constant value below a certain temperature.…”

“…However, some authors have reported that the disorder in such materials can in fact be a combination of both thermal and structural disorder, and hence also dependent on the temperature. [44][45][46] Indeed by analyzing our data from 288 K down to 78 K in steps of 30 K, systematic shift in the DOS can be observed as shown in Figure 6a. The DOS characteristic energy is also found to monotonically decrease with the decreasing temperature as plotted in Figure 6b.…”

“…Although such behavior discussed in this work still requires further verification, there have also been numerous reports that suggest a correlation between the width of the localized states distribution and the temperature. [45,46] Since the characteristics of the localized states DOS strongly affect the transport properties in non-crystalline semiconductors, we believe that including such phenomena into the transport theory could improve its effectiveness of explaining and predicting the experimental results further. of mobile carriers that can contribute to the conductivity as well as suggesting the presence of hole traps and/or fixed charges at the semiconductor/dielectric interface that can adversely affect the hole transport.…”

Drift-mobility measurements and mobility edges in disordered silicons

“…A more refined trapping model based on a linear g(E) at the transport edge, usually with an exponential form for deeper-lying states in the bandtails, also fits the high-temperature measurements satisfactorily (Marshall et al 1986, Street et al 1988, Nebel and Bauer 1989. However, the main difficulty with the trapping calculations is that they do not incorporate the temperature dependence of the conduction bandtail width that was subsequently reported in this same temperature regime by Aljishi et al (1990).…”

Effect of Structural Disorder on the Electronic Density of States in One-Dimensional Chain of Atoms

“…It is well known that for example amorphous silicon exhibits band structure with the DoS showing characteristic "tails" which extend beyond the originally placed band boundary for the crystal [12]. These tails correspond to localized states and so amorphisation may serve as an alternative possibility to introduce localized scattering centers, as it is known for the amorphous semiconducting silicon, instead of the standard doping technique.…”