Physico-Chemical nanomaterials science

Features of mechanically stimulated changes of electrical conductivity of X-irradiated p-Si crystals
Lys R.M., Pavlyk B.V., Didyk R.I., Shykorjak J.A.
Department of Sensor and Semiconductor Electronics, Ivan Franko National University of Lviv. Str. Tarnavskoho, 107, Lviv-79017, Ukraine. 
E-mail: lys_r@ukr.net.

The development of modern microelectronics and sensor technology is inextricably linked with the creation of functional materials based on silicon crystals with predetermined and stable physical properties.
Mechanically stimulated changes in the electrical conductivity of irradiated and non-irradiated p-Si crystals have been studied. It is established that a section of weak dependence of the change R(σ) begins to form with each subsequent compression-expansion cycle in the graph of resistance to mechanical load (R(σ)) on the initial section of the deformation action.
The mechanically stimulated increase in the value of the electrical resistance of the irradiated p-Si crystals is due to the generation of electrons, which in the process of deformation are captured by mobile dislocations and carried to the near-surface layer, where they recombine with the main charge carriers. After completion of recombination processes, mechano-stimulated changes in the resistance of the sample are described by the laws of unirradiated crystals.
As the number of cycles of elastic deformation in the crystal increases, both point and more complex lattice defects accumulate, which form clusters of different sizes due to the motion of dislocations. As a result, internal mechanical stresses are generated. These macro-defects are able to localize charges. Under uniaxial compression, mobile dislocations can facilitate the transfer of electrons to the crystal surface. The appearance of characteristic maxima on the dependence graph R(σ) can be an indicator of the beginning of irreversible mechanically stimulated changes in the crystal structure.