The list of my conference presentations and seminars in reverse chronological order


Invited Talks

  1. S. P. Łepkowski, “Polarization-induced phase transitions in InGaN-based coupled quantum wells”, 2nd International Conference on Physics and its Applications, Los Angeles, USA, 17-19 July 2023. (virtual presentation)

  2. S. P. Łepkowski, “Ab-initio calculations of higher-order elastic constants in crystals and their application to strain analysis in thin films”, International Conference on Materials Science, Engineering & Technology, Singapore, 7-9 September 2022. (virtual presentation)

  3. S. P. Łepkowski, “First-principles calculations of higher-order elastic constants”, Global Summit on Condensed Matter Physics (CONMAT2021), Valencia, Spain, 18-22 October 2021. (virtual presentation)

  4. S. P. Łepkowski, “Topological insulator in InGaN-based quantum wells”, 2nd International Conference on Semiconductors, Optoelectronics and Nanostructures, Barcelona, Spain, 19-20 August 2019.

  5. S. P. Łepkowski, “Piezoelectricity, elasticity, and deformation potentials in III-Nitrides”, 4th Workshop on Theory, Modelling and Computational Methods for Semiconductor Materials and Nanostructures, Salford, UK, 22-24 January 2014.

Contributed Talks

  1. S. P. Łepkowski, W. Bardyszewski, “Electric field driven topological phase transition in InN/GaN quantum wells”, 45th “Jaszowiec” International School and Conference on the Physics of Semiconductors, Szczyrk, Poland, 28-24 June 2016.

  2. W. Bardyszewski, S. P. Łepkowski, „ Theoretical study of excitonic g-factor in GaN/AlGaN and InGaN/GaN quantum wells”, 32nd International Conference on the Physics of Semiconductors, Austin, USA, 10.08-15.08 2014.

  3. S. P. Łepkowski, I. Gorczyca, „Influence of composition and atomic arrangement on elastic properties of wurtzite InGaN and InAlN alloys”, 40th “Jaszowiec” 2011 International School and Conference on the Physics of Semiconductors, Krynica-Zdrój, Polska, 25 June – 1 July 2011.

  4. S. P. Łepkowski, S. Krukowski, „Teoretyczna analiza prądu elektronowego w warstwach typu p azotkowych emiterów światła”, Warsztaty Laserowe, Instytut Technologii Elektronowej, Warszawa, Polska, 26-27 listopada 2007 (in polish).

  5. S. P. Łepkowski, “Effects of nonlinear elasticity and electromechanical coupling on pressure coefficient of the light emission in group-III nitride quantum structures”, Joint 21st AIRAPT and 45th EHPRG International Conference on High Pressure Science and Technology, Catania, Italy, 17-21 September, 2007.

  6. S. P. Łepkowski, J. A. Majewski, G. Jurczak, “Effects of Nonlinear Elasticity in Nitride Semiconductors and their Nanostructures”, 28th International Conference on the Physics of Semiconductors,Vienna, Austria, 24-28 July, 2006.

  7. S. P. Łepkowski, T. Suski, P. Perlin, T. Kitamura, Y. Ishida, H. Okumura, T. Onuma, T. Koida, S.F. Chichibu, “Manifestation of nonlinear elastic properties of InGaN”, 32th International School on the Physics of Semiconductor Compounds, Jaszowiec, Polska, 30 May-6 June 2003.

  8. H. Teisseyre, T. Suski, S. P. Łepkowski, S. Anceau, P. Perlin, P. Lefebvre, L. Kończewicz, H. Hirayama, Y. Aoyagi, „Small Built-in Electric Fields in Quaternary InAlGaN Hetrostructures”, International Workshop on Nitride Semiconductors, Aachen, Germany, 22-15 July 2002.

  9. S. P. Łepkowski, „Influence of polarization effects on optical transitions in AlGaN/GaN quantum wells”, Finnish-Polish Conference on Nitride Semiconductors, Helsinki, Finland, 17-18 October, 2000.

  10. S. P. Łepkowski, „Modelowanie transportu nośników ładunku w kwantowych przyrządach pólprzewodnikowych”, VI Konferencja Naukowa – Technologia Elektronowa, ELTE 97, Krynica Zdrój, Polska, 1997 (in polish).

  11. S. P. Łepkowski, W. Nakwaski, „Carrier transport modelling in VCSEL”, 5th Polish-Lithuanian Workshop on Physics of Semiconductors, Vilnius,Lithuania,1996.

Posters

  1. S. P. Łepkowski, A.R. Anwar, “Biaxial Relaxation Coefficient in Group-III Nitride Quantum Wells and Thin Films”, 49th International School & Conference on the Physics of Semiconductors “Jaszowiec 2021”, 1-10 September 2021. (virtual presentation)

  2. S. P. Łepkowski, W. Bardyszewski, “Topological quantum phase transition in InN/GaN quantum wells under hydrostatic pressure”, 11th International Conference on Nitride Semiconductors, Beijing, China, 2015.

  3. S. P. Łepkowski, W. Bardyszewski, D. Rodak, “Topological quantum phase transition in InN/GaN quantum wells under hydrostatic pressure”, 44th “Jaszowiec” International School and Conference on the Physics of Semiconductors, Wisła 2015.

  4. S. P. Łepkowski, W. Bardyszewski, D. Rodak, „Polarization-induced band inversion in In-rich InGaN/GaN quantum wells”, 43rd “Jaszowiec” International School and Conference on the Physics of Semiconductors, Wisła, 7.06-12.06 2014.

  5. S. P. Łepkowski, I. Gorczyca, „Absence of optical polarization switching in m-plane InGaN/GaN and AlGaN/AlN quantum wells”, 43rd “Jaszowiec” International School and Conference on the Physics of Semiconductors, Wisła, 7.06-12.06 2014.

  6. S. P. Łepkowski, I. Gorczyca, „Absence of optical polarization switching in m-plane InGaN/GaN and AlGaN/AlN quantum wells”, International Workshop on Nitride Semiconductors, Wrocław, 24.08-29.08 2014.

  7. S. P. Łepkowski, I. Gorczyca, K. Stefańska, N. E. Christensen, and A. Svane, “Deformation potentials in AlGaN and InGaN alloys from first principles calculations”, 42nd “Jaszowiec” International School and Conference on the Physics of Semiconductors, Wisła, Polska, 22 -27 June 2013.

  8. W. Bardyszewski, S. P. Łepkowski, „Optical properties of excitons in m-plane AlGaN/AlN quantum wells”, 42nd “Jaszowiec” International School and Conference on the Physics of Semiconductors, Wisła, Polska, 22 -27 June 2013.

  9. S. P. Łepkowski and I. Gorczyca, „Elastic properties of InGaN and InAlN from first-principles calculations”, 31st International Conference on the Physics of Semiconductors, Zurich, Switzerland, 29 July - 3 August 2012.

  10. W. Bardyszewski, S. P. Łepkowski, „Optical anisotropy in [0001] oriented GaN/AlGaN quantum wells under pressure”, 31st International Conference on the Physics of Semiconductors, Zurich, Switzerland, 29 July - 3 August 2012.

  11. S. P. Łepkowski, W. Bardyszewski, „Pressure-driven reordering of valence band states in GaN/AlxGa1-xN AlyGa1-yN/AlN quantum wells”, 41st “Jaszowiec” 2012 International School and Conference on the Physics of Semiconductors, Krynica-Zdrój, Polska, 8 -15 June 2012.

  12. W. Bardyszewski, S. P. Łepkowski, „Symmetry of the top valence band states in GaN/AlGaN quantum wells and its influence on the polarization of emitted light”, 40th “Jaszowiec” 2011 International School and Conference on the Physics of Semiconductors, Krynica-Zdrój, Polska, 25 June – 1 July 2011.

  13. S. P. Łepkowski, W. Bardyszewski, H. Teisseyre, „Effect of the built-in strain on the in-plane optical anisotropy of m-plane GaN/AlGaN quantum wells”, 40th “Jaszowiec” 2011 International School and Conference on the Physics of Semiconductors, Krynica-Zdrój, Polska, 25 June – 1 July 2011.

  14. S. P. Łepkowski, I. Gorczyca, „Pressure dependence of the light emission in zinc-blende InGaAs/GaAs and InGaN/GaN quantum wells : nonlinear elasticity and compositional effects”, 38th International School and Conference on the Physics of Semiconductors, “Jaszowiec” 2009, Krynica-Zdrój, Polska, 19-26 June 2009.

  15. S. P. Łepkowski, “Influence of nonlinear elasticity on the stress field induced by nitride quantum dots in a subsurface layer”, 29th International Conference on the Physics of Semiconductors, Rio de Janeiro, Brazil, 27 July – 1 August 2008.

  16. S. P. Łepkowski, “Influence of second-order piezoelectricity on the pressure coefficient of the light emission in (111)-oriented InGaAs/GaAs quantum wells”, 29th International Conference on the Physics of Semiconductors, Rio de Janeiro, Brazil, 27 July – 1 August 2008.

  17. S. P. Łepkowski, “Effect of nonlinear elasticity on interband and intersubband transition energies in nitride quantum wells and superlattices”, 36th International School on the Physics of Semiconductor Compounds, Jaszowiec, Polska, 9-15 June 2007.

  18. S. P. Łepkowski, J. A. Majewski, “Effects of nonlinear elasticity and electromechanical coupling on optical properties of nitride quantum wells”, 35th International School on the Physics of Semiconductor Compounds, Jaszowiec, Polska, 17-23 June 2006.

  19. S. P. Łepkowski, G. Jurczak , „Quantum Confined Stark Effect in vertically correlated GaN/AlN quantum dots”, 6th International Conference on Nitride Semiconductors, Bremen, Germany, 28 August - 2 September, 2005.

  20. S. P. Łepkowski, J. A. Majewski, G. Jurczak, “Nonlinear elasticity in wurtzite III-N heterostructures”, 34th International School on the Physics of Semiconductor Compounds, Jaszowiec, Polska, 4-10 June 2005.

  21. S. P. Łepkowski, J. A. Majewski, “Pressure dependence of elastic constants in wurtzite and zinc-blende nitrides and their influence on the optical pressure coefficients in nitride heterostructures”, 2004 Material Research Society Fall Meeting, Boston, USA, 28 November - 2 December, 2004.

  22. S. P. Łepkowski, G. Jurczak, P. Dłużewski, T. Suski, “Modeling of elastic, piezoelectric and optical properties of vertically correlated GaN/AlN quantum dots”, 2004 Material Research Society Fall Meeting, Boston, USA, 28 November - 2 December, 2004.

  23. S. P. Łepkowski, J. A. Majewski, „Pressure dependence of elastic constants in zinc-blende III-N and their influence on pressure coefficients of the light emission in cubic InGaN/GaN quantum wells”, 33th International School on the Physics of Semiconductor Compounds, Jaszowiec, Polska, 28 May-4 June 2004.

  24. S. Anceau, S. P. Łepkowski, H. Teisseyre, T. Suski, P. Perlin, P. Lefebvre, L. Kończewicz, H. Hirayama, Y. Aoyagi, “Small internal, electric fields in quaternary InAlGaN heterostructures”, NATO Advanced Research Workshop on UV Solid-State Light Emitters and Detectors, Vilnius, Lithuania, 17-21 June 2003.

  25. T. Suski, H. Teisseyre, S. P. Łepkowski, P. Perlin, T. Kitamura, Y. Ishida, H. Okumura, S. F. Chichibu, ”Pressure Coefficients of the Light Emission in Cubic InGaN epilayers and Cubic InGaN/GaN Quantum Wells”, International Workshop on Nitride Semiconductors, Aachen, Germany, 22-15 July 2002.

  26. C. Skierbiszewski, S. P. Łepkowski, P. Perlin, T. Suski, W. Jantsch, J. Geisz, “Effective mass and conduction band dispersion of GaAsN/GaAs quantum wells”, 10th International Conference on Modulated Semiconductor Structures, Linz, Austria, 23-27 July, 2001.

  27. S.P. Łepkowski, T. Suski, P. Perlin, V.Yu. Ivanov, M. Godlewski, N. Grandjean, J. Massies, “Free-Carrier Screening of Polarization Fields in Wurtzite AlGaN/GaN Quantum Heterostructures”, 30th International School on the Physics of Semiconductor Compounds, Jaszowiec, Polska, 1-8 June 2001.

  28. S. P. Łepkowski, M. Bugajski, “Theoretical analysis of optical gain in quantum well lasers including the valence band mixing effect”, 26th International School on the Physics of Semiconductor Compounds, Jaszowiec, Polska, 1997.

  29. S. P. Łepkowski, W. Nakwaski, „Analiza transportu nośników w laserach VCSEL, przy nierónomiernym rozkładzie temperatury wewnątrz struktury”, VI Konferencja Naukowa – Technologia Elektronowa, ELTE 97, Krynica Zdrój, Polska, 1997 (in polish).

Seminars

  1. S. P. Łepkowski, “Topologiczne przejście fazowe w studniach kwantowych InN/GaN i InGaN/GaN wywołane ciśnieniem hydrostatycznym i zewnętrznym polem elektrycznym”, Wydział Fizyki, Uniwersytet Warszawski, marzec 2017 (in polish).

  2. S. P. Łepkowski, “Topological phase transition in InN/GaN and InGaN/GaN quantum wells induced by hydrostatic pressure and external electric field”, Institute of High Pressure Physics PAS, February 2017.

  3. S. P. Łepkowski, „Własności sprężyste i piezoelektryczne azotkowych półprzewodników i struktur kwantowych”, Instytut Fizyki PAN, 6 marzec 2012 (in polish).

  4. S. P. Łepkowski, „Modelowanie nanostruktur półprzewodnikowych oraz o tym co łaczy fizyke ciała stałego i informtykę”, Wydział Matematyczno-Przyrodniczy, Uniwersytet Kardynała Stefana Wyszyńskiego, 6 grudnia 2011 (in polish).

  5. S. P. Łepkowski, „Nieliniowe efekty sprężyste i piezoelektryczne w studniach i kropkach kwantowych pod ciśnieniem”, Wydział Fizyki, Uniwersytet Warszawski, 27 luty 2009 (in polish).

  6. S. P. Łepkowski, „Własności optyczne laserów azotkowych”, Centrum Badań Wysokociśnieniowych PAN, 12 grudzień 2005 (in polish).

  7. S. P. Łepkowski, „Modelowanie laserów InGaN/GaN/AlGaN”, Centrum Badań Wysokociśnieniowych PAN, 27 kwiecień 2004 (in polish).

  8. S. P. Łepkowski, „Pressure-dependent elastic constants of zinc-blende GaN and InN”, Center for High Pressure Physics PAS, 14 January 2004.

  9. S. P. Łepkowski, „Azotkowe struktury kwantowe In(Al)GaN/GaN: nietypowe własności optyczne indukowane ciśnieniem hydrostatycznym cz. I i cz.II”, Instytut Podstawowych Problemów Techniki PAN, grudzień 2002 (in polish).

  10. S. P. Łepkowski, „Pole piezoelektryczne i jego wpływ na własności optyczne azotkowych studni kwantowych pod ciśnieniem hydrostatycznym”, Centrum Badań Wysokociśnieniowych PAN, marzec 2001 (in polish).