Mechanisms of Electron Scattering in Uniaxially Deformed Silicon Single Crystals with Radiation Defects

Temperature dependencies for Hall mobility of electrons for the uniaxially deformed n-Si single crystals, irradiated by the flow of electrons Ω=1·1017 el./cm2 with the energy of 12 MeV, are obtained on the basis of piezo-Hall effect measurements. From the analysis of these dependencies it follows that under the uniaxial pressure (0–0.42) GPa and (0–0.37) GPa along crystallographic directions [100] and [111], respectively, the deformation-induced increase of the Hall mobility has been observed. On the basis of the proposed theoretical model of mobility, this increase is explained by the decrease of the amplitude of a large-scale potential with an increase in the magnitude of uniaxial deformation and, accordingly, the probability of electron scattering on this potential. The slight discrepancy between the obtained experimental results and the relevant theoretical calculations at the low temperatures is due to the fact that the electron scattering on the radiation defects, created by the electron radiation, was not taken into account in the calculations. The decrease in Hall mobility of electrons along with an increase in temperature for unirradiated and irradiated silicon single crystals is explained by the growth of the probability of electron scattering on the optical phonons that are responsible for the intervalley scattering in silicon. The obtained results can be used in designing and modelling on the basis of n-Si single crystals of various electronic devices of micro- and nanoelectronics, which can be subject to the extreme conditions of action of the significant radiation and deformation fields

Electronic properties of potassium doped FePc

The evolution of electronic structure of the organic semiconductor iron-phthalocyanine with potassium doping has been studied by means of photoemission spectroscopy, near-edge X-ray absorption fine structure and density functional theory (DFT) calculations. The DFT study and detailed analysis of the core-level spectra permit us to suggest possible lattice sites for the potassium ions. The data disclosed filling of the lowest unoccupied molecular orbital upon doping and associated changes of the core level absorption spectra. None of the films prepared in our studies showed a finite electronic density of states at the Fermi level. (C) 2010 Elsevier B.V. All rights reserved