Physico-Chemical nanomaterials science

The role of dislocations in radiation-stimulated changes in the electrophysical and optical characteristics of silicon structures
Lys R.M., Pavlyk B.V., 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 nanoelectronics in terms of significant reduction of elements makes increased demands on the state of the near-surface layer of silicon structures. After all, unstable processes that occur at the boundaries of the separation under the influence of external factors determine the operational parameters of these elements. The presence of point and linear defects can significantly affect the activity of the surface. This can affect the efficiency and durability of solar cells under the action of weak electromagnetic fields.
The aim was to form a surface-barrier and light-emitting  structures (LES) based on p-Si crystals with different concentrations of dislocations on the surface of the semiconductor substrate and to investigate the change in their electrophysical and optical characteristics under the influence of X-rays. Changes in the surface resistance of silicon single crystals, volt-farad characteristics, the density of surface states, and electroluminescence of LES were analysed.
As the concentration of dislocations increases, the surface resistance of silicon increases. The reason is the process of generating the main charge carriers by linear defects. As the X-ray dose increases, the p-Si resistance increases further. The resistance of unirradiated and irradiated samples of solar silicon under elastic compression decreases. With increasing dislocation concentrations greater than 104 cm2, there is a certain nonmonotonicity of charge accumulation at the Si-SiO2 interface, which is associated with the additional influence of the mechanical field of dislocations and the electric field of the Cottrell cloud on X-stimulated changes in these structures.
It is shown that high concentrations of dislocations on the surface (111) of silicon are generated by the methods of plastic deformation and high-temperature annealing in an oxygen atmosphere. This allows creation of highly efficient radiating Al-Si(p) structures.