A richer
collection of barriers has been revealed at 80 K. The highest one nearly coincides in energy with E g (Φ 0≈1.1 eV with 95% confidence limits of 1.08 and 1.14 eV). A lower one Φ 1≈0.74 eV (with the 95% confidence limits of 0.66 and 0.78 eV) is close to the values ascribed in the literature to all Ni silicide barriers with n-type Si [17, 20, 21] (equality of barrier heights of all nickel silicides was explained by the presence of similar diffusion layers in all nickel silicide/silicon interfaces [20]). Estimation of the lowest one yields a figure of Φ 2≈0.51 eV (the 95% confidence band is from 0.48 to 0.54 eV); a barrier of this height, to our knowledge, has never been connected with a Ni silicide/Si transition in the literature.b However, we attribute all the above barriers to the Ni
silicide/poly-Si interface. 4EGI-1 molecular weight Our reasoning is as Tozasertib purchase follows. The band structure of a polysilicon film is known to be spatially inhomogeneous: A strong potential relief is associated with grain boundaries [24]. In n-Si, even in the heavily doped n + one, there may exist depleted or even p-type spatial domains [24] which, on the one hand, as a result of band-to-band transitions, may be sources of electron-hole pairs. In turn, these pairs are separated by the potential relief and generate the photo-emf of the observed polarity because, despite that the potential peaks should be more or less symmetrical and the electron-hole pairs should arise with close likelihoods
on both their slopes, a part of electrons escapes from the Si film accumulating in silicide, whereas holes are localized at the grain boundaries. This process may give rise to the Birinapant research buy photovoltage under irradiation by photons with energies . In addition to charge separation on opposite sides of the film, this process also increases the potential relief. ADP ribosylation factor On the other hand, grain boundaries may serve as potential barriers for electrons localized in n +-Si grains segregating them from the Ni silicide film and producing the photo-emf of the observed polarity due to electron injection into the silicide under the effect of photons with h ν