Physico-Chemical nanomaterials science

Radiative and magnetically stimulated changes of the charge states of the Si-SiO2 boundary in the diode structures with nanostructured dislocation complexes 
D.P. Slobodzyan1, M.O. Kushlyk1,2 R.M. Lys1, B.V. Pavlyk1
1 Department of Sensor and Semiconductor Electronics, Ivan Franko National University of Lviv, 79017, 107 Hen. Tarnavskoho Str., Lviv, Ukraine. 
Е-mail: slobodzyan_d@ukr.net
2 Institute of Physics PAS, Al. Lotników 32/46, Warsaw 02-668, Poland

Modern development of alternative energy highly requires materials useful as a base for solar cells fabrication. Recently, it was supposed that silicon has a certain spectrum of uncontrolled impurities, which significantly affect the stability of solar cells. In particular, the presence of isovalent impurities extremely affect the processes of defect formation and oxide diffusion processes in near-surface layers of silicon. It leads to the degradation of solar energy converters under radiation exposure and application of magnetic field (MF). In addition, the question of the influence of electromagnetic field on the elements with a certain concentration of linear defects remains open.
A boron doped Cz-p-Si samples were investigated for solar energy application. The dislocations were generated by one-axis plastic deformation of silicon crystals at 1000 K. Three surface sections with orientation (111) of the Si-crystal and dislocation concentration 102, 104, and 105 cm-2 was taken into account. The concentration of 102 cm-2 was considered as a dislocation-free crystal.
The studies of the Si-SiO2 boundary charge state for all surfaces sections were investigated over Bi-Si-Al diode structure formation. Electro-physical characterization of sample regions was applied together with calculations of surface density of charge states. Irradiation of samples was carried out with X-ray tube (V = 45 kV, I = 8 mA, W-anode). Magnetic field was applied with different duration and constant induction of 0.17 T.
It has been shown that the presence of controlled concentration of linear defects (> 102 cm-2) changes the p-Si surface spectrum and growing the number of hydrogen-containing defects in the places where dislocations reached the surface. At a certain stage, the irradiation and magnetic field effects weaken due to decrease or increase of a positive charge in SiO2.