Dr. Roland Tomašiūnas

Dr. Roland Tomašiūnas

Phone: +370 656 80 658

E-mail: 

Institute of Photonics and Nanotechnology (IPN)

Technology sciences, Materials Engineering (T 008); Natural sciences, Physics (N 002)

principal investigator, professor

MOCVD technology, nanotechnology, semiconductors, GaN and related compounds, oxides, quantum structures,non-linear optical structures, optical and electronic devices, hybrid structures and devices, photonic crystals, photonics.

I.Reklaitis, F.Nippert, R.Kudžma, T.Malinauskas, S.Karpov, I.Pietzonka, H.J.Lugauer, M.Strassburg, P.Vitta, R.Tomašiūnas, A.Hoffmann. Differential carrier lifetime in InGaN-based light-emitting diodes obtained by small-signal frequency-domain measurements. J. Appl. Phys. 121, 035701 (2017).

K.Nomeika, R.Aleksiejūnas, S.Miasojedovas, R.Tomašiūnas, K.Jarašiūnas, I.Pietzonka, M.Strassburg, H.-J.Lugauer. Impact of carrier localization and diffusion on photoluminescence in highly excited cyan and green InGaN LED structures. J. Lumin. 188, 301-306 (2017).

V.Svrcek, M.Kolenda, A.Kadys, I.Reklaitis, D.Dobrovolskas, T.Malinauskas, M.Lozach, D.Mariotti, M.Strassburg, R.Tomasiunas Significant carrier extraction enhancement at the interface of an InN/p-GaN heterojunction under reverse bias voltage. Nanomaterials 8, 1039 (2018).

I.Reklaitis, L.Krencius, T.Malinauskas, S.Yu.Karpov, H.J.Lugauer, I.Pietzonka, M.Strassburg, P.Vitta, R.Tomašiūnas. Time of carrier escape and recombination coefficients in InGaN quantum-well active regions of blue, cyan, and green light-emitting diodes. Semicond. Sci. Technol. 34, 015007 (2019).

P.Ščajev, D.Litvinas, G.Kreiza, S.Stanionytė, T.Malinauskas, R.Tomašiūnas, S.Juršėnas. Highly efficient nanocrystalline CsxMA1-xPbBr3 perovskite layers for white light generation. Nanotechnology 30, 345702 (2019).

M.Kolenda, D.Kezys, I.Reklaitis, E.Radiunas, R.Ritasalo, A.Kadys, T.Grinys, T.Malinauskas, S.Stanionytė, M.Skapas, R.Petruškevičius, R.Tomašiūnas. Development of polarity inversion in a GaN waveguide structure for modal phase matching. J. Mater. Sci. 55, 12008 (2020).

I.Reklaitis, E.Radiunas, T.Malinauskas, S.Stanionytė, G.Juška, R.Ritasalo, T.Pilvi, S.Taeger, M.Strassburg, R.Tomašiūnas. A comparative study on atomic layer deposited oxide film morphology and their electrical breakdown. Surf. Coat. Technol. 399, 126123 (2020).

E.Jelmakas, A.Kadys, M.Dmukauskas, T.Grinys, R.Tomašiūnas, D.Dobrovolskas, G.Gervinskas, S.Juodkazis, M.Talaikis, G.Niaura. FIB micro-milled sapphire for GaN maskless epitaxial lateral overgrowth: a systematic study on patterning geometry. J. Mater. Sci.: Mater. Electron. 32, 14532 (2021).

M.Kolenda, A.Kadys, T.Malinauskas, E.Radiunas, R.Ritasalo, R.Tomašiūnas. The importance of nucleation layer for the GaN N-face purity on the annealed Al2O3 layers deposited by atomic layer deposition. Mater. Sci. Engineer. B 284, 115850 (2022).

Research Council of Lithuania, Project “Production and investigation of advanced geometry nitride harmonic generators” (SMART, 2018-2021), coordinator.

JSPS Japan-Lithuanian Bilateral Joint Research Project „Development of GaN optical microresonators with polarity inversion.“ (Nr. P-LJB-21-9, 2021-2023), coordinator.

R.Tomašiūnas, I.Reklaitis, L.Krencius, P.Vitta, S.Karpov, H.J.Lugauer, M.Strassburg. Differential charge carrier lifetime investigated in a blue InGaN LED at operational conditions. 20th International Conference on Transparent Optical Networks, ICTON '18, July 5-9, 2018, Bucharest, Romania.

R.Tomašiūnas, I.Reklaitis, E.Radiunas, T.Malinauskas, S.Stanionytė, G.Juška, R.Ritasalo, T.Pilvi, S.Taeger, M.Mandl, M.Strassburg. ALD oxides as interfaces for GaN optoelectronic devices. 21st International Conference on Transparent Optical Networks, ICTON '19, July 9-13, 2019, Angers, France.

R.Tomašiūnas, I.Reklaitis, P.Vitta, F.Nippert, S.Karpov, H.J.Lugauer, M.Strassburg. Blue, cyan and green InGaN/GaN LEDs: investigation of differential charge carrier lifetime under working conditions. 15th IUPAC International Conference on Novel Materials and their Synthesis (NMS-XV), September 6-11, 2019, Shenyang, China.

Marek Kolenda (2017-2022)

“Advanced material microscopy” - for the first year master course students, Faculty of Physics.

"Metamaterials" - for second-year master course students, Faculty of Physics.

“Materials and their technologies for functional electronics and photonics” - for PhD students of the programme

“Materials engineering”, Faculty of Physics.

Martynas Klybas, bachelor student, Faculty of Physics - internship (2020) and bachelor thesis (2021).

Robertas Naumickas, bachelor student, Faculty of Physics - internship (2019) and bachelor thesis (2019).

Participation in the national/international governing bodies, commissions, committees, boards etc.

Member of the Committee for Doctoral studies "Materials Engineering" (T 008), Vilnius University.

Member of the Technical Committee 73 Nanotechnologies, Lithuanian Standards Board.

Expert of Latvian Science Council and Polish National Science Center.

H2020-MSCA-ITN expert.

Reviewer of MDPI, Elsevier, Springer, IOP journals.