Iryna Pundyk

Properties of Nanostructure Formed on SiO2/Si Interface by Laser Radiation

The aim of this work is to study optical properties of Si nanohills formed on the SiO2/Si interface by the pulsed Nd:YAG laser radiation. Nanohills which are self-organized on the surface of Si, are characterized by strong photoluminescence in the visible range of spectra with long wing in the red part of spectra. This peculiarity is explained by Quantum confinement effect in nanohillsnanowires with graded diameter. We have found a new method for graded band gap semiconductor formation using an elementary semiconductor. Graded change of band gap arises due to Quantum confinement effect.

P-N Junction Formation in ITO/p-Si Structure by Powerful Laser Radiation for Solar Cells Applications

The research report is devoted to the development of a new method of nanostructures formation in ITO/p-Si/Al structure with powerful laser radiation and study of its optical and electrical properties for solar cells applications. It was shown that after the structure irradiation by Nd:YAG laser second harmonic, dark current voltage characteristics become diode-like. Increase of ITO/p-Si/Al solar cell efficiency after irradiation by the laser, using photocurrent voltage characteristic method, was shown.

Laser-induced self-organization of nano-wires on SiO2/Si interface

Original observation of new graded band gap structures formed on the surface of elementary Si semiconductor at studying the optical properties of Si nano-hills formed at the SiO2/Si interface by pulsed Nd:YAG laser irradiation is reported. The self-organized nano-hills on Si surface are characterized by a strong photoluminescence in the visible range of spectrum with a shoulder extended to the long-wave part of the spectrum. The feature is explained by the quantum confinement effect in nano-hills-nano-wires of gradually changing diameter.

Relaxation of Resonant Excitons in CdSe Nanocrystals: Simple Variational Calculation

The details of energy relaxation and multiple phonon scattering of a resonantly excited electron-hole pair confined in CdSe nanoparticle are studied at low temperature. Simple variational calculation of Ritz type have been performed to explain relaxation of excitons resonantly excited in CdSe nanoparticles in the case if initial photon absorption and creation of electron-hole pair takes place in the peripheral part of nanoparticle.