Papers by Author: V. Khomenkov

Abstract: The effect of preparation conditions and annealing treatment on Si-rich-SiOx layers was investigated. It was observed that oxygen plays important role in the creation of light-emitting centres. It was found that the emission in the green-orange spectral range is connected with silicon oxide defects which contain dangling bonds. At the same time PL band in the infrared spectral range is caused by recombination of carriers in amorphous silicon or nanocrystalline one. It is shown that modification of defect content under various treatments gives the possibility to control the emission properties of the layers.

Abstract: Radiation hardness of silicon detectors based on thin epitaxial layer for the LHC upgrade was studied. No type inversion was observed after irradiation by 24 GeV protons in the fluence range (1.5–10)⋅1015 cm–2 due to overcompensating donor generation. After long-term annealing highly irradiated devices show decrease of effective doping concentration and then undergo type inversion. All mentioned means that thin epitaxial devices might be used for innermost layers of vertex detectors and need moderate cooling during beam off time. Properly chosen scenario might help to restore their working characteristics.

Abstract: The aging process of silicon nanostructures obtained by magnetron sputtering and electrochemical etching is investigated by photoluminescence and Raman scattering methods. It is shown that oxidation of silicon crystallites takes place in both types of structures and results in appearance of additional emission bands. However the degree of oxidation in etched structures exceeds significantly this value for sputtered samples. It is found that the intensity and spectral position of the emission band caused by exciton recombination in Si crystallites do not change practically during aging in sputtered structures in contrast to etched ones. It is shown that the oxidation of silicon amorphous phase occur during aging in sputtered structures.