Methods: 1. DFT (Density Functional Theory) as implemented in VASP. DFT allows computing numerous properties of materials from first principles. 2. MD (molecular dynamics, as implemented in VASP). MD allows accounting for effects of temperature. ; 3. Vibrational properties of solids from first principles using Phonopy and TDEP. 4. Structure prediction (Calypso) Publications: 1) Unraveling hidden Mg-Mn-H phase relations at high pressures and temperatures by in situ synchrotron diffraction K. Spektor, W. Crichton, S. Konar, S. Filippov, S. I. Simak, and U. Häussermann Inorg. Chem. 2018, 57, 1614−1622 2) First-principles theory of the temperature-induced phase transition in Li2C2. A manuscript in final preparation.

Methods: 1. µ-PL/µ-Raman polarization resolved spectroscopy under low and room temperatures. µ-PL allows one to deduce information of material's/defects' electronic structure. µ-Raman spectroscopy allows determining structural and electronic (under certain conditions) properties of the material or the defects. 2. µ-PLE (photoluminescence excitation) under low or ambient temperatures: this method helps to localize the electronic transitions contributing to the detected signal. ; 3. Temperature dependency of PL: this method gives further information about electronic transitions. Publications: 1.Strongly polarized quantum-dot-like light emitters embedded in GaAs/GaNAs core/shell nanowires // S. Filippov, M. Jansson, J. E. Stehr, J. Palisaitis, P. O. Å. Persson, F. Ishikawa, W. M. Chen and I. A. Buyanova // Nanoscale 8, 15939 (2016) 2. Core–shell carrier and exciton transfer in GaAs/GaNAs coaxial nanowires // S. Chen, M. Jansson, S. Filippov, F. Ishikawa, W. M. Chen and I. A. Buyanova // J. Vac. Sci. Technol. B 34, 04J104 (2016) 3. Structural properties of GaNAs nanowires probed by micro-Raman spectroscopy // S Filippov, F. Ishikawa, W. M. Chen and I. A. Buyanova // Semicond. Sci. Technol. 31, 0255002 (2016) 4. Exciton Fine-Structure Splitting in Self-Assembled Lateral InAs/GaAs Quantum-Dot Molecular Structures // S. Fillippov, Y. Puttisong, Y. Huang, I. A. Buyanova, S. Suraprapapich, C. W. Tu, and W. M. Chen // ACS Nano 9, 5741 (2015) 5. Origin of Strong Photoluminescence Polarization in GaNP Nanowires // S. Filippov, S. Sukrittanon, Y. Kuang, C. Tu, P. O. Å. Persson, W. M. Chen, and I. A. Buyanova //Nano lett. 14, 5624 (2014) 6. Origin of radiative recombination and manifestations of localization effects in GaAs/GaNAs core/shell nanowires // S. L. Chen, S. Filippov, F. Ishikawa, W. M. Chen and I. A. Buyanova // Appl. Phys. Lett. 105, 253106 (2014) 7. Effects of Ni-coating on ZnO nanowires: A Raman scattering study // S. Filippov, X. J. Wang, M. Devika, N. K. Reddy, C. W. Tu, W. M. Chen and I. A. Buyanova //J. Appl. Phys. 113, 214302 (2013) 8. Defects in N, O and N, Zn implanted ZnO bulk crystals // J. E. Stehr, X. J. Wang, S. Filippov, S. J. Pearton, I. G. Ivanov, W. M. Chen and I. A. Buyanova // J. Appl. Phys. 113, 103509 (2013) 9. Defect properties of ZnO nanowires revealed from an optically detected magnetic resonance study // J. E. Stehr, S. L. Chen, S. Filippov, M. Devika, N. K. Reddy, C. W. Tu, W. M. Chen and I. A. Buyanova //Nanotechnology 24, 015701 (2013) 10. Evidence for coupling between exciton emissions and surface plasmon in Ni-coated ZnO nanowires // . Q. J. Ren, S. Filippov, S. L. Chen, M. Devika, N. K. Reddy, C. W. Tu, W. M. Chen and I. A. Buyanova // Nanotechnology 23, 425201 (2012)

IFM, Condensed Matter Physics

РФФ, Applied Mathematics and Physics

РФФ, Applied Mathematics and Physics